{"id":91,"date":"2018-11-15T12:08:16","date_gmt":"2018-11-15T12:08:16","guid":{"rendered":"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/?post_type=chapter&#038;p=91"},"modified":"2022-01-07T05:41:11","modified_gmt":"2022-01-07T05:41:11","slug":"confinement-of-a-particle-in-a-box-and-in-3d-quantum-dot","status":"publish","type":"chapter","link":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/chapter\/confinement-of-a-particle-in-a-box-and-in-3d-quantum-dot\/","title":{"rendered":"Confinement of a particle in a box and in 3D (Quantum Dot)"},"content":{"raw":"<div><span style=\"float: right;\"><a href=\"https:\/\/youtu.be\/uG0D05Nw6wI\" target=\"_blank\" rel=\"noopener noreferrer\"><img src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"epgp books\" width=\"75px\" height=\"75px;\" \/><\/a>\r\n<\/span><\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n3.1 Confinement of a particle\r\n\r\n3.1.1 Particle in 1D box\r\n\r\n3.1.1a Particle in 1D infinite box\r\n\r\n3.1.1b Particle in 1D finite box\r\n\r\n3.1.2 Particle in 2D box\r\n\r\n3.1.2a Particle in 2D rectangular infinite box\r\n\r\n3.1.2b Particle in 2D circular box\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>3.1 CONFINEMENT<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify;\">The properties of materials are strongly influenced by the size of the particle. For example Carbon is a non-metal but when considered at the nanoscale single layer allotrope of carbon i.e. Graphene is one of the best conductors. The phenomenon that can be used to explain the size dependent characteristics of materials is Quantum confinement.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify;\">Quantum confinement effects are generally observed when the size of the particle is small and comparable to the de Broglie wavelength of the electron. The effect describes the phenomenon resulting due to squeezing the particles (electrons and holes) into a dimension that approaches a classical limit so that various quantum effects are manifested. In this regime, energy of the particle is no longer continuous, but discrete.<\/p>\r\n&nbsp;\r\n<p style=\"text-align: justify;\">Quantum confinement effects are observed in low dimension, two, one or zero dimension. When a particle is confined in two dimension (2D) or in a plane, then particle\u2019s motion is quantized along the direction of confinement, say z-axis and the particle motion is classical i.e. is free to move in the x-y plane. The systems in 2D is also known as \u201cquantum well\u201d. In case one dimension (1D), particle\u2019s motion is quantized due to confinement in 2D (say in x-y plane) and classical in 1D along z-axis. The system in 1D is also known as \u201cquantum wire\u201d. In case of zero dimension (0D), particle\u2019s motion is quantized in all three dimension due to confinement along x,y and z directions and known as \u201cquantum dot\u201d. In these systems, the spatial dimensions are of the order of the de Broglie wavelength of the carriers and therefore, the carrier energy states become quantised. As a result, the electronic, electrical and optical\u00a0<span style=\"font-size: 1em; text-align: initial;\">behaviour of the carriers are governed by quantum mechanics along one dimension, two dimension and all three dimensions in quantum well (2D), quamtum wire (1D) and quantum dot (0D), respectively.<\/span><\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>Calculation of eigenstates and eigenvalues for different system<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify;\">The particle\u2019s motion in quantum wells, wires and dots can be described using the analogy to a particle in 1D box, a 2D box, and a 3D box, respectively. The energies of the carrier along the direction of confinement are no longer continuous as in the case where there is no confinement. The emergence of discrete states from continuum states is the most fundamental signature of nanomaterials or nanosystems. One has to solve the Schrodinger equation of the carrier to find out particle\u2019s eigenvalues and eigenfunctions. This is achieved by solving differential equations with particular boundary conditions which can be used to predict the actual shape of a quantum well, wire or dot.<\/p>\r\n&nbsp;\r\n\r\n<strong>3.1.1a Particle in 1D infinite box<\/strong>\r\n\r\n<\/div>\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-178\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111.png\" alt=\"\" width=\"487\" height=\"344\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">For this the boundary conditions are<\/span>\r\n\r\n<img class=\"aligncenter size-full wp-image-179\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-112.png\" alt=\"\" width=\"74\" height=\"61\" \/>\r\n\r\n<span style=\"font-size: 1em; text-align: initial;\">The Schrodinger equation to solve is<\/span>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-180\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-113.png\" alt=\"\" width=\"158\" height=\"40\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Rearranging to yield in the box region where V=0<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-181\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-114.png\" alt=\"\" width=\"117\" height=\"43\" \/>\r\n\r\nWhere k<sup>2<\/sup> = 2mE\/h<sup>2<\/sup> and general solution is\r\n\r\n<img class=\"aligncenter size-full wp-image-182\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-115.png\" alt=\"\" width=\"162\" height=\"35\" \/>\r\n\r\nApplying the boundary conditions\r\n\r\n<img class=\"aligncenter size-full wp-image-183\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-116.png\" alt=\"\" width=\"223\" height=\"51\" \/>\r\n\r\nThis leads to\r\n\r\n<img class=\"aligncenter size-full wp-image-184\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-117.png\" alt=\"\" width=\"121\" height=\"70\" \/>\r\n\r\nAnd by normalizing the wave function we get,\r\n\r\n<img class=\"aligncenter size-full wp-image-185\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118.png\" alt=\"\" width=\"309\" height=\"300\" \/>\r\n\r\n<span style=\"font-size: 1em; text-align: initial;\">Particle energies, wavefunctions, and probability densities for n = 0, 1 and 2.<\/span>\r\n\r\n&nbsp;\r\n\r\n<strong style=\"text-align: initial; font-size: 1em;\">3.1.1b Particle in a 1D finite box<\/strong>\r\n\r\n&nbsp;\r\n\r\n<span style=\"text-align: justify; font-size: 1em;\">From quantum mechanics we know that as the potential is zero inside box, the solutions in the box region will be wavelike and in the barrier region the solution will be exponentially decaying. The potential is<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-189\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122.png\" alt=\"\" width=\"428\" height=\"335\" \/>\r\n\r\nThe solutions in the three regions indicated are\r\n\r\n<img class=\"aligncenter size-full wp-image-191\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124.png\" alt=\"\" width=\"430\" height=\"142\" \/>\r\n<p style=\"text-align: justify;\">By applying the boundary conditions, B=0 and F=0 due to finiteness of the wavefunction outside the box, we get<\/p>\r\n<img class=\"aligncenter size-full wp-image-192\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-125.png\" alt=\"\" width=\"115\" height=\"32\" \/>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-193\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126.png\" alt=\"\" width=\"541\" height=\"469\" \/>\r\n\r\nNow by applying\u00a0 the boundary conditions at the interface, one gets\r\n\r\nHere either we get the trivial solution where A=B=C=D or that the determent of the large matrix is zero\r\n\r\n<img class=\"aligncenter size-full wp-image-194\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-127.png\" alt=\"\" width=\"254\" height=\"90\" \/>\r\n\r\nTo simplify the determent we have apply the following path as\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-195\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128.png\" alt=\"\" width=\"306\" height=\"150\" \/>\r\n\r\n<img class=\"aligncenter size-full wp-image-196\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129.png\" alt=\"\" width=\"526\" height=\"616\" \/>\r\n\r\n<\/div>\r\n<img class=\"aligncenter size-full wp-image-197\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130.png\" alt=\"\" width=\"535\" height=\"128\" \/><img class=\"aligncenter size-full wp-image-198\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131.png\" alt=\"\" width=\"457\" height=\"194\" \/>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>3.1.2\u00a0 Particle in 2D box<\/strong>\r\n\r\n&nbsp;\r\n\r\n<strong>3.1.2a Particle in a rectangular box<\/strong>\r\n\r\n&nbsp;\r\n\r\n<span style=\"font-size: 1em; text-align: initial;\">The potential is<\/span>\r\n\r\n<\/div>\r\n<div><\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-199\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132.png\" alt=\"\" width=\"509\" height=\"143\" \/>\r\n\r\nThe Schrodinger equation to solve is\r\n\r\n<img class=\"aligncenter size-full wp-image-200\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133.png\" alt=\"\" width=\"344\" height=\"40\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Let us consider solution of above equation is \u00a0\u00a0( ,\u00a0 ) = ; where , are the functions of x and y only.<\/span>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Substituting the solution in eq. 3.15 and rearranging the terms to yield in the box region where V=0, the eq. 3.15 becomes<\/span>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify;\"><span style=\"text-align: initial; font-size: 1em;\">Let us consider E= E<sub>x<\/sub>+E<sub>y<\/sub> and using variable separable method for a rectangular box eq. 3.16 transforms into two equations each consisting of one variable only.<\/span><\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-202\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-135.png\" alt=\"\" width=\"151\" height=\"51\" \/><img class=\"aligncenter size-full wp-image-203\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136.png\" alt=\"\" width=\"560\" height=\"406\" \/><img class=\"aligncenter size-full wp-image-204\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137.png\" alt=\"\" width=\"443\" height=\"301\" \/>\r\n\r\nAnd by normalizing the wavefunction we get,\r\n\r\n<img class=\"aligncenter size-full wp-image-205\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-138.png\" alt=\"\" width=\"291\" height=\"52\" \/>\r\n\r\n<\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<strong>3.1.2b Particle in circular box<\/strong>\r\n\r\n&nbsp;\r\n<p style=\"text-align: justify;\">Now, consider a circular box of radius R. The potential inside the box is 0 and outside of the box is \u221e such that the boundary conditions for the wave function would be<\/p>\r\n<img class=\"aligncenter size-full wp-image-206\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-139.png\" alt=\"\" width=\"108\" height=\"35\" \/>\r\n\r\n&nbsp;\r\n\r\nTransforming the Schrodinger question from Cartesian co-ordinates to polar coordinates, the transformation equations are\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-207\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140.png\" alt=\"\" width=\"515\" height=\"486\" \/><img class=\"aligncenter size-full wp-image-208\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141.png\" alt=\"\" width=\"644\" height=\"467\" \/><img class=\"aligncenter size-full wp-image-209\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142.png\" alt=\"\" width=\"663\" height=\"271\" \/>\r\n\r\nSchrodinger equation for circular box becomes\r\n\r\n<img class=\"aligncenter size-full wp-image-210\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143.png\" alt=\"\" width=\"384\" height=\"66\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Considering the solution for the above equation,<\/span>\r\n\r\n<img class=\"aligncenter size-full wp-image-211\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-144.png\" alt=\"\" width=\"144\" height=\"28\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Substituting into Schrodinger equation,<\/span>\r\n\r\n<img class=\"aligncenter size-full wp-image-212\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145.png\" alt=\"\" width=\"389\" height=\"60\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">Rearranging above equation,<\/span>\r\n\r\n<img class=\"aligncenter size-full wp-image-213\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146.png\" alt=\"\" width=\"530\" height=\"84\" \/>\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">This is form of Bessel differential equation. To change into standard form, considering the variable<\/span>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-214\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147.png\" alt=\"\" width=\"415\" height=\"117\" \/>\r\n\r\nThe Schrodinger equation finally reduces to,\r\n\r\n<img class=\"aligncenter size-full wp-image-215\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148.png\" alt=\"\" width=\"324\" height=\"63\" \/>\r\n\r\nTaking the solution of the above equation to be\r\n\r\n<\/div>\r\n<img class=\"aligncenter size-full wp-image-216\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149.png\" alt=\"\" width=\"419\" height=\"143\" \/>\r\n<div><img class=\"aligncenter size-full wp-image-217\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150.png\" alt=\"\" width=\"572\" height=\"386\" \/><\/div>\r\n<div><\/div>\r\n<div style=\"text-align: justify;\"><span style=\"text-align: initial; font-size: 1em;\">This Bessel Function\u2019s expansion remains an infinite series which never truncates. The quantization occurs only with the boundary conditions i.e. at the perimeter of circular ring. At the boundary (r=R) Bessel function should be zero, let us say it, 0. So,<\/span><\/div>\r\n<div><img class=\"aligncenter size-full wp-image-219\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152.png\" alt=\"\" width=\"435\" height=\"331\" \/><\/div>\r\n<div style=\"text-align: justify;\">\r\n\r\n&nbsp;\r\n\r\n<\/div>\r\n<div><\/div>\r\n<strong>3.2 Particle in 3D box<\/strong>\r\n<strong>3.2.1a Particle in an infinite cubical box<\/strong>\r\n\r\nLet us consider a general case i.e. a box with dimensions a, b and c:\r\n\r\nThe potential is\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-220\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153.png\" alt=\"\" width=\"365\" height=\"99\" \/>\r\n\r\nThe Schrodinger equation to solve is\r\n\r\n<img class=\"aligncenter size-full wp-image-221\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154.png\" alt=\"\" width=\"418\" height=\"43\" \/>\r\n<p style=\"text-align: justify;\">Let us consider solution of above equation is \u00a0\u00a0( ,\u00a0 ,\u00a0 ) = ; where , are the functions of only x, y and z respectively.<\/p>\r\n&nbsp;\r\n\r\nSubstituting the solution in eq. 3.29 and rearranging the terms to yield in the box region where V=0, the eq. 3.29 becomes\r\n\r\n<img class=\"aligncenter size-full wp-image-222\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-155.png\" alt=\"\" width=\"294\" height=\"55\" \/>\r\n<p style=\"text-align: justify;\">Let us consider = E<sub>x<\/sub>+E<sub>y<\/sub> +Ez and using variable separable method for a rectangular box eq. 3.30 transforms into two equations each consisting of one variable only.<\/p>\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-223\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156.png\" alt=\"\" width=\"604\" height=\"214\" \/>\r\n\r\nFor this the boundary conditions are\r\n\r\n<img class=\"aligncenter size-full wp-image-224\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-157.png\" alt=\"\" width=\"93\" height=\"179\" \/>\r\n\r\nApplying the boundary conditions\r\n\r\n<\/div>\r\n<div>\r\n<div><\/div>\r\n<div><\/div>\r\n<img class=\"aligncenter size-full wp-image-225\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-158.png\" alt=\"\" width=\"222\" height=\"71\" \/>\r\n\r\nThis leads to\r\n\r\n<img class=\"aligncenter size-full wp-image-226\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159.png\" alt=\"\" width=\"538\" height=\"597\" \/>\r\n\r\n<\/div>\r\n<div><strong style=\"font-size: 1em; text-align: initial;\">3.2.1b Particle in a spherical box<\/strong><\/div>\r\n<div>\r\n\r\n&nbsp;\r\n\r\nLet us consider a spherical box of radius R. The potential inside the box is 0 and outside of the box is \u221e\r\n\r\n<img class=\"aligncenter size-full wp-image-227\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-160.png\" alt=\"\" width=\"190\" height=\"50\" \/>\r\n\r\nsuch that the boundary conditions for the wave function would be\r\n\r\n<img class=\"aligncenter size-full wp-image-228\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-161.png\" alt=\"\" width=\"149\" height=\"33\" \/>\r\n<p style=\"text-align: justify;\"><span style=\"font-size: 1em; text-align: initial;\">Transforming the Schrodinger question from Cartesian co-ordinates to polar coordinates, the transformation equation are<\/span><\/p>\r\n\r\n<\/div>\r\n<img class=\"aligncenter size-full wp-image-229\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162.png\" alt=\"\" width=\"650\" height=\"413\" \/>\r\n<div><\/div>\r\n<div><\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-230\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163.png\" alt=\"\" width=\"643\" height=\"288\" \/><img class=\"aligncenter size-full wp-image-231\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-164.png\" alt=\"\" width=\"291\" height=\"96\" \/>\r\n\r\nEquations 3.38 and 3.39 are angular and radial equations respectively.\r\n\r\n<\/div>\r\n<div>\r\n\r\n<img class=\"aligncenter size-full wp-image-232\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165.png\" alt=\"\" width=\"574\" height=\"547\" \/>\r\n\r\nEquations (3.39), (3.40) and (3.41) and the functions of only r,\u00a0 and respectively.\r\n\r\nTaking, Solution of eq 3.41 be \u00a0(\u00a0 ) \u221d\r\n\r\n<img class=\"aligncenter size-full wp-image-233\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166.png\" alt=\"\" width=\"506\" height=\"398\" \/>\r\n\r\n<span style=\"font-size: 1em; text-align: initial; text-indent: 1em;\">Which is form of Legendre\u2019s equation.<\/span>\r\n\r\n&nbsp;\r\n\r\n<span style=\"text-align: initial; font-size: 1em;\">This equation will have a solution only if<\/span>\r\n\r\n<\/div>\r\n<div><\/div>\r\n<img class=\"aligncenter size-full wp-image-234\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-167.png\" alt=\"\" width=\"162\" height=\"93\" \/>\r\n\r\n<span style=\"font-size: 1em; text-align: initial;\">The solution Legendre\u2019s function will be<\/span>\r\n<div>\r\n\r\n&nbsp;\r\n\r\n<img class=\"aligncenter size-full wp-image-237\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-170.png\" alt=\"\" width=\"291\" height=\"47\" \/>\r\n\r\nThere angular part of the solution will be\r\n\r\n<img class=\"aligncenter size-full wp-image-236\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169.png\" alt=\"\" width=\"436\" height=\"38\" \/>\r\n\r\n<img class=\"aligncenter size-full wp-image-238\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171.png\" alt=\"\" width=\"614\" height=\"460\" \/>\r\n\r\nThis equation is of the form of Bessel\u2019s equation. R(r) are the spherical Bessel functions then,\r\n\r\n<img class=\"aligncenter size-full wp-image-239\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172.png\" alt=\"\" width=\"555\" height=\"185\" \/>\r\n<p style=\"text-align: justify;\">The spherical Bessel functions are oscillatory in nature and have zero many times. The functions ( ) are not square-integrable at r=0, whereas the functions ( ) are well defined in the entire region. Hence ( ) are unphysical, and that the radial wavefunction \u00a0, ( ) is thus only proportional to ( ). The general solution of the Schrodinger equation is<\/p>\r\n\r\n<\/div>\r\n<img class=\"aligncenter size-full wp-image-240\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-173.png\" alt=\"\" width=\"253\" height=\"37\" \/>\r\n<p style=\"text-align: justify;\">In order to satisfy the boundary condition at r=R, the value of k must be chosen such a way so that z=kR corresponds to one of the zeros of ( ) and given by<\/p>\r\n<img class=\"aligncenter size-full wp-image-241\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-174.png\" alt=\"\" width=\"69\" height=\"33\" \/>\r\n\r\nfor n=1,2,3.\r\n\r\n&nbsp;\r\n\r\nTherefore the allowed energy states will be\r\n\r\n<img class=\"aligncenter size-full wp-image-242\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-175.png\" alt=\"\" width=\"152\" height=\"65\" \/>\r\n<table>\r\n<tbody>\r\n<tr>\r\n<td><strong>you can view video on Confinement of a particle in a box and in 3D (Quantum Dot)<\/strong><\/td>\r\n<td><a href=\"https:\/\/youtu.be\/uG0D05Nw6wI\" target=\"_blank\" rel=\"noopener noreferrer\"><img class=\"alignnone wp-image-120\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"\" width=\"36\" height=\"36\" \/><\/a><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>","rendered":"<div><span style=\"float: right;\"><a href=\"https:\/\/youtu.be\/uG0D05Nw6wI\" target=\"_blank\" rel=\"noopener noreferrer\"><img decoding=\"async\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"epgp books\" width=\"75px\" height=\"75px;\" \/><\/a><br \/>\n<\/span><\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>3.1 Confinement of a particle<\/p>\n<p>3.1.1 Particle in 1D box<\/p>\n<p>3.1.1a Particle in 1D infinite box<\/p>\n<p>3.1.1b Particle in 1D finite box<\/p>\n<p>3.1.2 Particle in 2D box<\/p>\n<p>3.1.2a Particle in 2D rectangular infinite box<\/p>\n<p>3.1.2b Particle in 2D circular box<\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>3.1 CONFINEMENT<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">The properties of materials are strongly influenced by the size of the particle. For example Carbon is a non-metal but when considered at the nanoscale single layer allotrope of carbon i.e. Graphene is one of the best conductors. The phenomenon that can be used to explain the size dependent characteristics of materials is Quantum confinement.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">Quantum confinement effects are generally observed when the size of the particle is small and comparable to the de Broglie wavelength of the electron. The effect describes the phenomenon resulting due to squeezing the particles (electrons and holes) into a dimension that approaches a classical limit so that various quantum effects are manifested. In this regime, energy of the particle is no longer continuous, but discrete.<\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">Quantum confinement effects are observed in low dimension, two, one or zero dimension. When a particle is confined in two dimension (2D) or in a plane, then particle\u2019s motion is quantized along the direction of confinement, say z-axis and the particle motion is classical i.e. is free to move in the x-y plane. The systems in 2D is also known as \u201cquantum well\u201d. In case one dimension (1D), particle\u2019s motion is quantized due to confinement in 2D (say in x-y plane) and classical in 1D along z-axis. The system in 1D is also known as \u201cquantum wire\u201d. In case of zero dimension (0D), particle\u2019s motion is quantized in all three dimension due to confinement along x,y and z directions and known as \u201cquantum dot\u201d. In these systems, the spatial dimensions are of the order of the de Broglie wavelength of the carriers and therefore, the carrier energy states become quantised. As a result, the electronic, electrical and optical\u00a0<span style=\"font-size: 1em; text-align: initial;\">behaviour of the carriers are governed by quantum mechanics along one dimension, two dimension and all three dimensions in quantum well (2D), quamtum wire (1D) and quantum dot (0D), respectively.<\/span><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>Calculation of eigenstates and eigenvalues for different system<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">The particle\u2019s motion in quantum wells, wires and dots can be described using the analogy to a particle in 1D box, a 2D box, and a 3D box, respectively. The energies of the carrier along the direction of confinement are no longer continuous as in the case where there is no confinement. The emergence of discrete states from continuum states is the most fundamental signature of nanomaterials or nanosystems. One has to solve the Schrodinger equation of the carrier to find out particle\u2019s eigenvalues and eigenfunctions. This is achieved by solving differential equations with particular boundary conditions which can be used to predict the actual shape of a quantum well, wire or dot.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>3.1.1a Particle in 1D infinite box<\/strong><\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-178\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111.png\" alt=\"\" width=\"487\" height=\"344\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111.png 487w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111-300x212.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111-65x46.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111-225x159.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-111-350x247.png 350w\" sizes=\"auto, (max-width: 487px) 100vw, 487px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">For this the boundary conditions are<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-179\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-112.png\" alt=\"\" width=\"74\" height=\"61\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-112.png 74w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-112-65x54.png 65w\" sizes=\"auto, (max-width: 74px) 100vw, 74px\" \/><\/p>\n<p><span style=\"font-size: 1em; text-align: initial;\">The Schrodinger equation to solve is<\/span><\/p>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-180\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-113.png\" alt=\"\" width=\"158\" height=\"40\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-113.png 158w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-113-65x16.png 65w\" sizes=\"auto, (max-width: 158px) 100vw, 158px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Rearranging to yield in the box region where V=0<\/span><\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-181\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-114.png\" alt=\"\" width=\"117\" height=\"43\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-114.png 117w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-114-65x24.png 65w\" sizes=\"auto, (max-width: 117px) 100vw, 117px\" \/><\/p>\n<p>Where k<sup>2<\/sup> = 2mE\/h<sup>2<\/sup> and general solution is<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-182\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-115.png\" alt=\"\" width=\"162\" height=\"35\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-115.png 162w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-115-65x14.png 65w\" sizes=\"auto, (max-width: 162px) 100vw, 162px\" \/><\/p>\n<p>Applying the boundary conditions<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-183\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-116.png\" alt=\"\" width=\"223\" height=\"51\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-116.png 223w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-116-65x15.png 65w\" sizes=\"auto, (max-width: 223px) 100vw, 223px\" \/><\/p>\n<p>This leads to<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-184\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-117.png\" alt=\"\" width=\"121\" height=\"70\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-117.png 121w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-117-65x38.png 65w\" sizes=\"auto, (max-width: 121px) 100vw, 121px\" \/><\/p>\n<p>And by normalizing the wave function we get,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-185\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118.png\" alt=\"\" width=\"309\" height=\"300\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118.png 309w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118-300x291.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118-65x63.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-118-225x218.png 225w\" sizes=\"auto, (max-width: 309px) 100vw, 309px\" \/><\/p>\n<p><span style=\"font-size: 1em; text-align: initial;\">Particle energies, wavefunctions, and probability densities for n = 0, 1 and 2.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong style=\"text-align: initial; font-size: 1em;\">3.1.1b Particle in a 1D finite box<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: justify; font-size: 1em;\">From quantum mechanics we know that as the potential is zero inside box, the solutions in the box region will be wavelike and in the barrier region the solution will be exponentially decaying. The potential is<\/span><\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-189\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122.png\" alt=\"\" width=\"428\" height=\"335\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122.png 428w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122-300x235.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122-65x51.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122-225x176.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-122-350x274.png 350w\" sizes=\"auto, (max-width: 428px) 100vw, 428px\" \/><\/p>\n<p>The solutions in the three regions indicated are<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-191\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124.png\" alt=\"\" width=\"430\" height=\"142\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124.png 430w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124-300x99.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124-65x21.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124-225x74.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-124-350x116.png 350w\" sizes=\"auto, (max-width: 430px) 100vw, 430px\" \/><\/p>\n<p style=\"text-align: justify;\">By applying the boundary conditions, B=0 and F=0 due to finiteness of the wavefunction outside the box, we get<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-192\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-125.png\" alt=\"\" width=\"115\" height=\"32\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-125.png 115w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-125-65x18.png 65w\" sizes=\"auto, (max-width: 115px) 100vw, 115px\" \/><\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-193\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126.png\" alt=\"\" width=\"541\" height=\"469\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126.png 541w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126-300x260.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126-65x56.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126-225x195.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-126-350x303.png 350w\" sizes=\"auto, (max-width: 541px) 100vw, 541px\" \/><\/p>\n<p>Now by applying\u00a0 the boundary conditions at the interface, one gets<\/p>\n<p>Here either we get the trivial solution where A=B=C=D or that the determent of the large matrix is zero<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-194\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-127.png\" alt=\"\" width=\"254\" height=\"90\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-127.png 254w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-127-65x23.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-127-225x80.png 225w\" sizes=\"auto, (max-width: 254px) 100vw, 254px\" \/><\/p>\n<p>To simplify the determent we have apply the following path as<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-195\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128.png\" alt=\"\" width=\"306\" height=\"150\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128.png 306w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128-300x147.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128-65x32.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-128-225x110.png 225w\" sizes=\"auto, (max-width: 306px) 100vw, 306px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-196\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129.png\" alt=\"\" width=\"526\" height=\"616\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129.png 526w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129-256x300.png 256w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129-65x76.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129-225x263.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-129-350x410.png 350w\" sizes=\"auto, (max-width: 526px) 100vw, 526px\" \/><\/p>\n<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-197\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130.png\" alt=\"\" width=\"535\" height=\"128\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130.png 535w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130-300x72.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130-65x16.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130-225x54.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-130-350x84.png 350w\" sizes=\"auto, (max-width: 535px) 100vw, 535px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-198\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131.png\" alt=\"\" width=\"457\" height=\"194\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131.png 457w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131-300x127.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131-65x28.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131-225x96.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-131-350x149.png 350w\" sizes=\"auto, (max-width: 457px) 100vw, 457px\" \/><\/p>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>3.1.2\u00a0 Particle in 2D box<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>3.1.2a Particle in a rectangular box<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 1em; text-align: initial;\">The potential is<\/span><\/p>\n<\/div>\n<div><\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-199\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132.png\" alt=\"\" width=\"509\" height=\"143\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132.png 509w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132-300x84.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132-65x18.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132-225x63.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-132-350x98.png 350w\" sizes=\"auto, (max-width: 509px) 100vw, 509px\" \/><\/p>\n<p>The Schrodinger equation to solve is<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-200\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133.png\" alt=\"\" width=\"344\" height=\"40\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133.png 344w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133-300x35.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133-65x8.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-133-225x26.png 225w\" sizes=\"auto, (max-width: 344px) 100vw, 344px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Let us consider solution of above equation is \u00a0\u00a0( ,\u00a0 ) = ; where , are the functions of x and y only.<\/span><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Substituting the solution in eq. 3.15 and rearranging the terms to yield in the box region where V=0, the eq. 3.15 becomes<\/span><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\"><span style=\"text-align: initial; font-size: 1em;\">Let us consider E= E<sub>x<\/sub>+E<sub>y<\/sub> and using variable separable method for a rectangular box eq. 3.16 transforms into two equations each consisting of one variable only.<\/span><\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-202\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-135.png\" alt=\"\" width=\"151\" height=\"51\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-135.png 151w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-135-150x51.png 150w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-135-65x22.png 65w\" sizes=\"auto, (max-width: 151px) 100vw, 151px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-203\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136.png\" alt=\"\" width=\"560\" height=\"406\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136.png 560w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136-300x218.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136-65x47.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136-225x163.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-136-350x254.png 350w\" sizes=\"auto, (max-width: 560px) 100vw, 560px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-204\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137.png\" alt=\"\" width=\"443\" height=\"301\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137.png 443w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137-300x204.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137-65x44.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137-225x153.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-137-350x238.png 350w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><\/p>\n<p>And by normalizing the wavefunction we get,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-205\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-138.png\" alt=\"\" width=\"291\" height=\"52\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-138.png 291w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-138-65x12.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-138-225x40.png 225w\" sizes=\"auto, (max-width: 291px) 100vw, 291px\" \/><\/p>\n<\/div>\n<div>\n<p>&nbsp;<\/p>\n<p><strong>3.1.2b Particle in circular box<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify;\">Now, consider a circular box of radius R. The potential inside the box is 0 and outside of the box is \u221e such that the boundary conditions for the wave function would be<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-206\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-139.png\" alt=\"\" width=\"108\" height=\"35\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-139.png 108w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-139-65x21.png 65w\" sizes=\"auto, (max-width: 108px) 100vw, 108px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>Transforming the Schrodinger question from Cartesian co-ordinates to polar coordinates, the transformation equations are<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-207\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140.png\" alt=\"\" width=\"515\" height=\"486\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140.png 515w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140-300x283.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140-65x61.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140-225x212.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-140-350x330.png 350w\" sizes=\"auto, (max-width: 515px) 100vw, 515px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-208\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141.png\" alt=\"\" width=\"644\" height=\"467\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141.png 644w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141-300x218.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141-65x47.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141-225x163.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-141-350x254.png 350w\" sizes=\"auto, (max-width: 644px) 100vw, 644px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-209\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142.png\" alt=\"\" width=\"663\" height=\"271\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142.png 663w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142-300x123.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142-65x27.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142-225x92.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-142-350x143.png 350w\" sizes=\"auto, (max-width: 663px) 100vw, 663px\" \/><\/p>\n<p>Schrodinger equation for circular box becomes<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-210\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143.png\" alt=\"\" width=\"384\" height=\"66\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143.png 384w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143-300x52.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143-65x11.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143-225x39.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-143-350x60.png 350w\" sizes=\"auto, (max-width: 384px) 100vw, 384px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Considering the solution for the above equation,<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-211\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-144.png\" alt=\"\" width=\"144\" height=\"28\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-144.png 144w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-144-65x13.png 65w\" sizes=\"auto, (max-width: 144px) 100vw, 144px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Substituting into Schrodinger equation,<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-212\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145.png\" alt=\"\" width=\"389\" height=\"60\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145.png 389w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145-300x46.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145-65x10.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145-225x35.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-145-350x54.png 350w\" sizes=\"auto, (max-width: 389px) 100vw, 389px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">Rearranging above equation,<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-213\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146.png\" alt=\"\" width=\"530\" height=\"84\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146.png 530w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146-300x48.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146-65x10.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146-225x36.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-146-350x55.png 350w\" sizes=\"auto, (max-width: 530px) 100vw, 530px\" \/><\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">This is form of Bessel differential equation. To change into standard form, considering the variable<\/span><\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-214\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147.png\" alt=\"\" width=\"415\" height=\"117\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147.png 415w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147-300x85.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147-65x18.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147-225x63.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-147-350x99.png 350w\" sizes=\"auto, (max-width: 415px) 100vw, 415px\" \/><\/p>\n<p>The Schrodinger equation finally reduces to,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-215\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148.png\" alt=\"\" width=\"324\" height=\"63\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148.png 324w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148-300x58.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148-65x13.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-148-225x44.png 225w\" sizes=\"auto, (max-width: 324px) 100vw, 324px\" \/><\/p>\n<p>Taking the solution of the above equation to be<\/p>\n<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-216\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149.png\" alt=\"\" width=\"419\" height=\"143\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149.png 419w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149-300x102.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149-65x22.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149-225x77.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-149-350x119.png 350w\" sizes=\"auto, (max-width: 419px) 100vw, 419px\" \/><\/p>\n<div><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-217\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150.png\" alt=\"\" width=\"572\" height=\"386\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150.png 572w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150-300x202.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150-65x44.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150-225x152.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-150-350x236.png 350w\" sizes=\"auto, (max-width: 572px) 100vw, 572px\" \/><\/div>\n<div><\/div>\n<div style=\"text-align: justify;\"><span style=\"text-align: initial; font-size: 1em;\">This Bessel Function\u2019s expansion remains an infinite series which never truncates. The quantization occurs only with the boundary conditions i.e. at the perimeter of circular ring. At the boundary (r=R) Bessel function should be zero, let us say it, 0. So,<\/span><\/div>\n<div><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-219\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152.png\" alt=\"\" width=\"435\" height=\"331\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152.png 435w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152-300x228.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152-65x49.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152-225x171.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-152-350x266.png 350w\" sizes=\"auto, (max-width: 435px) 100vw, 435px\" \/><\/div>\n<div style=\"text-align: justify;\">\n<p>&nbsp;<\/p>\n<\/div>\n<div><\/div>\n<p><strong>3.2 Particle in 3D box<\/strong><br \/>\n<strong>3.2.1a Particle in an infinite cubical box<\/strong><\/p>\n<p>Let us consider a general case i.e. a box with dimensions a, b and c:<\/p>\n<p>The potential is<\/p>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-220\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153.png\" alt=\"\" width=\"365\" height=\"99\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153.png 365w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153-300x81.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153-65x18.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153-225x61.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-153-350x95.png 350w\" sizes=\"auto, (max-width: 365px) 100vw, 365px\" \/><\/p>\n<p>The Schrodinger equation to solve is<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-221\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154.png\" alt=\"\" width=\"418\" height=\"43\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154.png 418w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154-300x31.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154-65x7.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154-225x23.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-154-350x36.png 350w\" sizes=\"auto, (max-width: 418px) 100vw, 418px\" \/><\/p>\n<p style=\"text-align: justify;\">Let us consider solution of above equation is \u00a0\u00a0( ,\u00a0 ,\u00a0 ) = ; where , are the functions of only x, y and z respectively.<\/p>\n<p>&nbsp;<\/p>\n<p>Substituting the solution in eq. 3.29 and rearranging the terms to yield in the box region where V=0, the eq. 3.29 becomes<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-222\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-155.png\" alt=\"\" width=\"294\" height=\"55\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-155.png 294w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-155-65x12.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-155-225x42.png 225w\" sizes=\"auto, (max-width: 294px) 100vw, 294px\" \/><\/p>\n<p style=\"text-align: justify;\">Let us consider = E<sub>x<\/sub>+E<sub>y<\/sub> +Ez and using variable separable method for a rectangular box eq. 3.30 transforms into two equations each consisting of one variable only.<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-223\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156.png\" alt=\"\" width=\"604\" height=\"214\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156.png 604w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156-300x106.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156-65x23.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156-225x80.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-156-350x124.png 350w\" sizes=\"auto, (max-width: 604px) 100vw, 604px\" \/><\/p>\n<p>For this the boundary conditions are<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-224\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-157.png\" alt=\"\" width=\"93\" height=\"179\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-157.png 93w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-157-65x125.png 65w\" sizes=\"auto, (max-width: 93px) 100vw, 93px\" \/><\/p>\n<p>Applying the boundary conditions<\/p>\n<\/div>\n<div>\n<div><\/div>\n<div><\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-225\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-158.png\" alt=\"\" width=\"222\" height=\"71\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-158.png 222w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-158-65x21.png 65w\" sizes=\"auto, (max-width: 222px) 100vw, 222px\" \/><\/p>\n<p>This leads to<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-226\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159.png\" alt=\"\" width=\"538\" height=\"597\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159.png 538w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159-270x300.png 270w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159-65x72.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159-225x250.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-159-350x388.png 350w\" sizes=\"auto, (max-width: 538px) 100vw, 538px\" \/><\/p>\n<\/div>\n<div><strong style=\"font-size: 1em; text-align: initial;\">3.2.1b Particle in a spherical box<\/strong><\/div>\n<div>\n<p>&nbsp;<\/p>\n<p>Let us consider a spherical box of radius R. The potential inside the box is 0 and outside of the box is \u221e<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-227\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-160.png\" alt=\"\" width=\"190\" height=\"50\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-160.png 190w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-160-65x17.png 65w\" sizes=\"auto, (max-width: 190px) 100vw, 190px\" \/><\/p>\n<p>such that the boundary conditions for the wave function would be<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-228\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-161.png\" alt=\"\" width=\"149\" height=\"33\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-161.png 149w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-161-65x14.png 65w\" sizes=\"auto, (max-width: 149px) 100vw, 149px\" \/><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-size: 1em; text-align: initial;\">Transforming the Schrodinger question from Cartesian co-ordinates to polar coordinates, the transformation equation are<\/span><\/p>\n<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-229\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162.png\" alt=\"\" width=\"650\" height=\"413\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162.png 650w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162-300x191.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162-65x41.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162-225x143.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-162-350x222.png 350w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><\/p>\n<div><\/div>\n<div><\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-230\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163.png\" alt=\"\" width=\"643\" height=\"288\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163.png 643w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163-300x134.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163-65x29.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163-225x101.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-163-350x157.png 350w\" sizes=\"auto, (max-width: 643px) 100vw, 643px\" \/><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-231\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-164.png\" alt=\"\" width=\"291\" height=\"96\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-164.png 291w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-164-65x21.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-164-225x74.png 225w\" sizes=\"auto, (max-width: 291px) 100vw, 291px\" \/><\/p>\n<p>Equations 3.38 and 3.39 are angular and radial equations respectively.<\/p>\n<\/div>\n<div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-232\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165.png\" alt=\"\" width=\"574\" height=\"547\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165.png 574w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165-300x286.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165-65x62.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165-225x214.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-165-350x334.png 350w\" sizes=\"auto, (max-width: 574px) 100vw, 574px\" \/><\/p>\n<p>Equations (3.39), (3.40) and (3.41) and the functions of only r,\u00a0 and respectively.<\/p>\n<p>Taking, Solution of eq 3.41 be \u00a0(\u00a0 ) \u221d<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-233\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166.png\" alt=\"\" width=\"506\" height=\"398\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166.png 506w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166-300x236.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166-65x51.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166-225x177.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-166-350x275.png 350w\" sizes=\"auto, (max-width: 506px) 100vw, 506px\" \/><\/p>\n<p><span style=\"font-size: 1em; text-align: initial; text-indent: 1em;\">Which is form of Legendre\u2019s equation.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"text-align: initial; font-size: 1em;\">This equation will have a solution only if<\/span><\/p>\n<\/div>\n<div><\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-234\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-167.png\" alt=\"\" width=\"162\" height=\"93\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-167.png 162w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-167-65x37.png 65w\" sizes=\"auto, (max-width: 162px) 100vw, 162px\" \/><\/p>\n<p><span style=\"font-size: 1em; text-align: initial;\">The solution Legendre\u2019s function will be<\/span><\/p>\n<div>\n<p>&nbsp;<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-237\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-170.png\" alt=\"\" width=\"291\" height=\"47\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-170.png 291w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-170-65x10.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-170-225x36.png 225w\" sizes=\"auto, (max-width: 291px) 100vw, 291px\" \/><\/p>\n<p>There angular part of the solution will be<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-236\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169.png\" alt=\"\" width=\"436\" height=\"38\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169.png 436w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169-300x26.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169-65x6.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169-225x20.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-169-350x31.png 350w\" sizes=\"auto, (max-width: 436px) 100vw, 436px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-238\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171.png\" alt=\"\" width=\"614\" height=\"460\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171.png 614w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171-300x225.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171-65x49.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171-225x169.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-171-350x262.png 350w\" sizes=\"auto, (max-width: 614px) 100vw, 614px\" \/><\/p>\n<p>This equation is of the form of Bessel\u2019s equation. R(r) are the spherical Bessel functions then,<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-239\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172.png\" alt=\"\" width=\"555\" height=\"185\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172.png 555w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172-300x100.png 300w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172-65x22.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172-225x75.png 225w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-172-350x117.png 350w\" sizes=\"auto, (max-width: 555px) 100vw, 555px\" \/><\/p>\n<p style=\"text-align: justify;\">The spherical Bessel functions are oscillatory in nature and have zero many times. The functions ( ) are not square-integrable at r=0, whereas the functions ( ) are well defined in the entire region. Hence ( ) are unphysical, and that the radial wavefunction \u00a0, ( ) is thus only proportional to ( ). The general solution of the Schrodinger equation is<\/p>\n<\/div>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-240\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-173.png\" alt=\"\" width=\"253\" height=\"37\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-173.png 253w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-173-65x10.png 65w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-173-225x33.png 225w\" sizes=\"auto, (max-width: 253px) 100vw, 253px\" \/><\/p>\n<p style=\"text-align: justify;\">In order to satisfy the boundary condition at r=R, the value of k must be chosen such a way so that z=kR corresponds to one of the zeros of ( ) and given by<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-241\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-174.png\" alt=\"\" width=\"69\" height=\"33\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-174.png 69w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-174-65x31.png 65w\" sizes=\"auto, (max-width: 69px) 100vw, 69px\" \/><\/p>\n<p>for n=1,2,3.<\/p>\n<p>&nbsp;<\/p>\n<p>Therefore the allowed energy states will be<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-242\" src=\"http:\/\/phy12.epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/sites\/96\/2018\/11\/2-175.png\" alt=\"\" width=\"152\" height=\"65\" srcset=\"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-175.png 152w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-175-150x65.png 150w, https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-content\/uploads\/sites\/96\/2018\/11\/2-175-65x28.png 65w\" sizes=\"auto, (max-width: 152px) 100vw, 152px\" \/><\/p>\n<table>\n<tbody>\n<tr>\n<td><strong>you can view video on Confinement of a particle in a box and in 3D (Quantum Dot)<\/strong><\/td>\n<td><a href=\"https:\/\/youtu.be\/uG0D05Nw6wI\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-120\" src=\"http:\/\/epgpbooks.inflibnet.ac.in\/wp-content\/uploads\/2018\/11\/download.png\" alt=\"\" width=\"36\" height=\"36\" \/><\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"author":3,"menu_order":7,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["prof-subhasis-ghosh"],"pb_section_license":""},"chapter-type":[],"contributor":[58],"license":[],"class_list":["post-91","chapter","type-chapter","status-publish","hentry","contributor-prof-subhasis-ghosh"],"part":3,"_links":{"self":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapters\/91","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/wp\/v2\/users\/3"}],"version-history":[{"count":10,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapters\/91\/revisions"}],"predecessor-version":[{"id":946,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapters\/91\/revisions\/946"}],"part":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapters\/91\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/wp\/v2\/media?parent=91"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/pressbooks\/v2\/chapter-type?post=91"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/wp\/v2\/contributor?post=91"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/ebooks.inflibnet.ac.in\/phy12\/wp-json\/wp\/v2\/license?post=91"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}