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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">najo</journal-id><journal-title-group><journal-title xml:lang="en">Nanosystems: Physics, Chemistry, Mathematics</journal-title><trans-title-group xml:lang="ru"><trans-title>Наносистемы: физика, химия, математика</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2220-8054</issn><issn pub-type="epub">2305-7971</issn><publisher><publisher-name>Университет ИТМО</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.17586/2220-8054-2022-13-2-156-163</article-id><article-id custom-type="elpub" pub-id-type="custom">najo-227</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>Статьи</subject></subj-group></article-categories><title-group><article-title>On the discrete spectrum of a quantum waveguide with Neumann windows in presence of exterior field</article-title><trans-title-group xml:lang="ru"><trans-title></trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Bagmutov</surname><given-names>A. S.</given-names></name></name-alternatives><email xlink:type="simple">bagmutov94@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Najar</surname><given-names>H. .</given-names></name></name-alternatives><email xlink:type="simple">hatemnajar@ipeim.rnu.tn</email><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Melikhov</surname><given-names>I. F.</given-names></name></name-alternatives><email xlink:type="simple">ivan.melikhov@gmail.com</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="western" xml:lang="en"><surname>Popov</surname><given-names>I. Y.</given-names></name></name-alternatives><email xlink:type="simple">popov1955@gmail.com</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="en">ITMO University<country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="en">Facultedes Sciences de Moanstir<country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2022</year></pub-date><pub-date pub-type="epub"><day>06</day><month>06</month><year>2025</year></pub-date><volume>13</volume><issue>2</issue><fpage>156</fpage><lpage>163</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Bagmutov A.S., Najar H..., Melikhov I.F., Popov I.Y., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Bagmutov A.S., Najar H..., Melikhov I.F., Popov I.Y.</copyright-holder><copyright-holder xml:lang="en">Bagmutov A.S., Najar H..., Melikhov I.F., Popov I.Y.</copyright-holder><license license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://nanojournal.ifmo.ru/jour/article/view/227">https://nanojournal.ifmo.ru/jour/article/view/227</self-uri><abstract><p>The discrete spectrum of the Hamiltonian describing a quantum particle living in three dimensional straight layer of width d in the presence of a constant electric field of strength F is studied. The Neumann boundary conditions are imposed on a finite set of bounded domains (windows) posed at one of the boundary planes and the Dirichlet boundary conditions on the remaining part of the boundary (it is a reduced problem for two identical coupled layers with symmetric electric field). It is proved that such system has eigenvalues below the lower bound of the essential spectrum for any F ≥ 0. Then we closer examine a dependence of bound state energies on F and window’s parameters, using numerical methods.</p></abstract><kwd-group xml:lang="en"><kwd>quantum waveguide</kwd><kwd>Schrodinger operator</kwd><kwd>discrete spectrum</kwd></kwd-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Borisov D., Exner P. and Gadyl’shin R., Krejcirik D. Bound states in weakly deformed strips and layers. 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