Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well

Abstract We discuss the influence of several factors on the deviations from energy spectrum of an infinite square quantum well (QW) for real microscopic systems that can be approximately modelled using particle in a box. We introduce the “blurring” potential in the form of the modified Woods-Saxon p...

Full description

Bibliographic Details
Main Author: Vladimir Ivchenko
Format: Article
Language:Portuguese
Published: Sociedade Brasileira de Física 2019-11-01
Series:Revista Brasileira de Ensino de Física
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172020000100410&tlng=en
_version_ 1798014969880510464
author Vladimir Ivchenko
author_facet Vladimir Ivchenko
author_sort Vladimir Ivchenko
collection DOAJ
description Abstract We discuss the influence of several factors on the deviations from energy spectrum of an infinite square quantum well (QW) for real microscopic systems that can be approximately modelled using particle in a box. We introduce the “blurring” potential in the form of the modified Woods-Saxon potential and solve the corresponding Schrödinger equation. It is found that the increase of the degree of blurring δ of the QW leads to the increase of number of the energy levels inside it and to increase of deviations from the quadratic dependence ε (n) (ε is the particle energy, n is the energy level number) typical for the infinite square QW, especially, for the energy levels close to the QW “tops”. It is most surprising that for relatively “large” values of δ the difference between the levels energies of such well and the appropriate (with the same n) levels energies of the square QW with the same depth changes sign (from positive to negative) as number n increases. We also conclude that the asymmetry of the QW and non-equality m i n ≠ m o u t (where m i n and m o u t are the particle effective mass inside and outside the QW) play a significant role for the relatively “shallow” well near the QW top.
first_indexed 2024-04-11T15:26:42Z
format Article
id doaj.art-57f138661a37464797c9797db2c2adab
institution Directory Open Access Journal
issn 1806-9126
language Portuguese
last_indexed 2024-04-11T15:26:42Z
publishDate 2019-11-01
publisher Sociedade Brasileira de Física
record_format Article
series Revista Brasileira de Ensino de Física
spelling doaj.art-57f138661a37464797c9797db2c2adab2022-12-22T04:16:14ZporSociedade Brasileira de FísicaRevista Brasileira de Ensino de Física1806-91262019-11-014210.1590/1806-9126-rbef-2019-0222Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square wellVladimir Ivchenkohttps://orcid.org/0000-0001-7367-3669Abstract We discuss the influence of several factors on the deviations from energy spectrum of an infinite square quantum well (QW) for real microscopic systems that can be approximately modelled using particle in a box. We introduce the “blurring” potential in the form of the modified Woods-Saxon potential and solve the corresponding Schrödinger equation. It is found that the increase of the degree of blurring δ of the QW leads to the increase of number of the energy levels inside it and to increase of deviations from the quadratic dependence ε (n) (ε is the particle energy, n is the energy level number) typical for the infinite square QW, especially, for the energy levels close to the QW “tops”. It is most surprising that for relatively “large” values of δ the difference between the levels energies of such well and the appropriate (with the same n) levels energies of the square QW with the same depth changes sign (from positive to negative) as number n increases. We also conclude that the asymmetry of the QW and non-equality m i n ≠ m o u t (where m i n and m o u t are the particle effective mass inside and outside the QW) play a significant role for the relatively “shallow” well near the QW top.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172020000100410&tlng=eninfinite square quantum wellthe “blurring” potentialthe asymmetry of QWthe position-dependent effective mass
spellingShingle Vladimir Ivchenko
Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
Revista Brasileira de Ensino de Física
infinite square quantum well
the “blurring” potential
the asymmetry of QW
the position-dependent effective mass
title Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
title_full Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
title_fullStr Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
title_full_unstemmed Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
title_short Quantitative analysis of the applicability limits of the model of a one-dimensional infinite square well
title_sort quantitative analysis of the applicability limits of the model of a one dimensional infinite square well
topic infinite square quantum well
the “blurring” potential
the asymmetry of QW
the position-dependent effective mass
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-11172020000100410&tlng=en
work_keys_str_mv AT vladimirivchenko quantitativeanalysisoftheapplicabilitylimitsofthemodelofaonedimensionalinfinitesquarewell