<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "JATS-journalpublishing1-3.dtd">
<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="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">bsuir</journal-id><journal-title-group><journal-title xml:lang="ru">Доклады БГУИР</journal-title><trans-title-group xml:lang="en"><trans-title>Doklady BGUIR</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1729-7648</issn><issn pub-type="epub">2708-0382</issn><publisher><publisher-name>БГУИР</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.35596/1729-7648-2019-126-8-38-42</article-id><article-id custom-type="elpub" pub-id-type="custom">bsuir-2416</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>ЭЛЕКТРОНИКА, РАДИОФИЗИКА, РАДИОТЕХНИКА, ИНФОРМАТИКА</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>ELECTRONICS, RADIOPHYSICS, RADIOENGINEERING, INFORMATICS</subject></subj-group></article-categories><title-group><article-title>SPECTRUMS OF SUPERCONDUCTING STATES AND TRIPLET EFFECTS IN SUPERCONDUCTOR/FERROMAGNET MULTILAYERS</article-title><trans-title-group xml:lang="en"><trans-title>SPECTRUMS OF SUPERCONDUCTING STATES AND TRIPLET EFFECTS IN SUPERCONDUCTOR/FERROMAGNET MULTILAYERS</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Kushnir</surname><given-names>V. N.</given-names></name><name name-style="western" xml:lang="en"><surname>Kushnir</surname><given-names>V. N.</given-names></name></name-alternatives><bio xml:lang="ru"><p>Kushnir Vasiliy Nikolayevich, D.Sci., Professor of the Department of Theoretical Physics and Astrophysics</p><p>220030, Minsk, Nezalejnasci av., 4</p></bio><bio xml:lang="en"><p>Kushnir Vasiliy Nikolayevich, D.Sci., Professor of the Department of Theoretical Physics and Astrophysics</p><p>220030, Minsk, Nezalejnasci av., 4</p></bio><email xlink:type="simple">vnkushnir@gmail.com</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Belarusian State University of Informatics and Radioelectronics; Belarusian State University</institution></aff><aff xml:lang="en"><institution>Belarusian State University of Informatics and Radioelectronics; Belarusian State University</institution></aff></aff-alternatives><pub-date pub-type="collection"><year>2019</year></pub-date><pub-date pub-type="epub"><day>29</day><month>12</month><year>2019</year></pub-date><volume>0</volume><issue>7-8</issue><fpage>38</fpage><lpage>42</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Kushnir V.N., 2019</copyright-statement><copyright-year>2019</copyright-year><copyright-holder xml:lang="ru">Kushnir V.N.</copyright-holder><copyright-holder xml:lang="en">Kushnir V.N.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" 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://doklady.bsuir.by/jour/article/view/2416">https://doklady.bsuir.by/jour/article/view/2416</self-uri><abstract><p>We report the results of studies of triplet superconductivity in structures with alternating superconductor and ferromagnet layers, as a part of the general problem of the properties of the spectra of superconductivity states depending on the magnetic state of the multilayer structure. Ferromagnetic layers are assumed monodomain and possessing inplane magnetic moments. In numerical examples, we used the parameters of the well-studied Nb/PdNi system. The critical temperatures and distributions of singlet and triplet currents depending on the relative orientation of the magnetic moments of the ferromagnetic layers are calculated in the formalism of the Usadel equations for 5- and 3-layer irregular structures. The following results are obtained. (1) The channeling effect of triplet pairs by a narrow central layer of a superconductor with complete suppression of the singlet component in it was confirmed. (2) The “0–1”-transition between the phases of a superconducting condensate of opposite symmetry induced by the transport current is predicted. (3) The effect of a double crossover of states on the dependence of the critical temperature, Tc, versus the angle θ between the magnetic moments of the ferromagnetic layers adjacent to the central layer of the superconductor in a 3-layer structure is predicted. The crossovers are reflected by a sharp turns in the Tc (θ) curve, while the infinitely small asymmetry of the structure eliminates the non-analyticity of this characteristic.</p></abstract><trans-abstract xml:lang="en"><p>We report the results of studies of triplet superconductivity in structures with alternating superconductor and ferromagnet layers, as a part of the general problem of the properties of the spectra of superconductivity states depending on the magnetic state of the multilayer structure. Ferromagnetic layers are assumed monodomain and possessing inplane magnetic moments. In numerical examples, we used the parameters of the well-studied Nb/PdNi system. The critical temperatures and distributions of singlet and triplet currents depending on the relative orientation of the magnetic moments of the ferromagnetic layers are calculated in the formalism of the Usadel equations for 5- and 3-layer irregular structures. The following results are obtained. (1) The channeling effect of triplet pairs by a narrow central layer of a superconductor with complete suppression of the singlet component in it was confirmed. (2) The “0–1”-transition between the phases of a superconducting condensate of opposite symmetry induced by the transport current is predicted. (3) The effect of a double crossover of states on the dependence of the critical temperature, Tc, versus the angle θ between the magnetic moments of the ferromagnetic layers adjacent to the central layer of the superconductor in a 3-layer structure is predicted. The crossovers are reflected by a sharp turns in the Tc (θ) curve, while the infinitely small asymmetry of the structure eliminates the non-analyticity of this characteristic.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>Odd-frequency triplet superconductivity</kwd><kwd>Usadel equations</kwd></kwd-group><kwd-group xml:lang="en"><kwd>Odd-frequency triplet superconductivity</kwd><kwd>Usadel equations</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">Buzdin A.I. Proximity effects in superconductor-ferromagnet heterostructures. Rev. Mod. Phys. 2005;77:935-976. DOI: 10.1103/RevModPhys.77.935</mixed-citation><mixed-citation xml:lang="en">Buzdin A.I. Proximity effects in superconductor-ferromagnet heterostructures. Rev. Mod. Phys. 2005;77:935-976. DOI: 10.1103/RevModPhys.77.935</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Bergeret F.S., Volkov A.F., Efetov K.B. Odd triplet superconductivity and related phenomena in superconductor-ferromagnet structures. Rev. Mod. Phys. 2005;77:1321-1373. DOI: 10.1103/RevModPhys.77.1321</mixed-citation><mixed-citation xml:lang="en">Bergeret F.S., Volkov A.F., Efetov K.B. Odd triplet superconductivity and related phenomena in superconductor-ferromagnet structures. Rev. Mod. Phys. 2005;77:1321-1373. DOI: 10.1103/RevModPhys.77.1321</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N., Sidorenko Anatolie, Tagirov L.R., Kupriyanov M.Yu. Basic superconducting spin valves. In: Sidorenko A. (ed.) Functional nanostructures and metamaterials for superconducting spintronics. Cham, Switzerland: Springer Int. Pub. AG, part of Springer Nature; 2018;1-29. DOI: 10.1007/978-3-319-90481-8_1</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N., Sidorenko Anatolie, Tagirov L.R., Kupriyanov M.Yu. Basic superconducting spin valves. In: Sidorenko A. (ed.) Functional nanostructures and metamaterials for superconducting spintronics. Cham, Switzerland: Springer Int. Pub. AG, part of Springer Nature; 2018;1-29. DOI: 10.1007/978-3-319-90481-8_1</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Tagirov L.R., Kupriyanov M.Yu., Kushnir V.N., Sidorenko Anatolie. Superconducting triplet proximity and Josephson spin valves. In: Sidorenko A. (ed.) Functional nanostructures and metamaterials for superconducting spintronics. Cham, Switzerland: Springer Int. Pub. AG, part of Springer Nature; 2018;31-47. DOI: 10.1007/978-3-319-90481-8_2</mixed-citation><mixed-citation xml:lang="en">Tagirov L.R., Kupriyanov M.Yu., Kushnir V.N., Sidorenko Anatolie. Superconducting triplet proximity and Josephson spin valves. In: Sidorenko A. (ed.) Functional nanostructures and metamaterials for superconducting spintronics. Cham, Switzerland: Springer Int. Pub. AG, part of Springer Nature; 2018;31-47. DOI: 10.1007/978-3-319-90481-8_2</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N. [Superconductivity of layered structures]. Minsk: BNTU; 2010. (In Russ.)</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N. [Superconductivity of layered structures]. Minsk: BNTU; 2010. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N. [Multimode phase transition to superconductivity in superconductor/ferromagnet multilayers]. Doklady NAN Belarusi = Reports of the Academy of sciences of Belarus. 2008;52(2):39-42. (In Russ.)</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N. [Multimode phase transition to superconductivity in superconductor/ferromagnet multilayers]. Doklady NAN Belarusi = Reports of the Academy of sciences of Belarus. 2008;52(2):39-42. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N., Kupriyanov M.Yu. Critical states of superconductivity and their crossover in multilayer Superconductor/Ferromagnet structures. JETP Letters. 2011;93:539-544. DOI: 10.1134/S0021.364011090086</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N., Kupriyanov M.Yu. Critical states of superconductivity and their crossover in multilayer Superconductor/Ferromagnet structures. JETP Letters. 2011;93:539-544. DOI: 10.1134/S0021.364011090086</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N., Prischepa S.L., Cirillo C., Vecchione A., Attanasio C., Kupriyanov M.Yu., Aarts J. Multiple order parameter configurations in superconductor/ferromagnet multilayers. Phys. Rev. B. 2011;84:214512(1-10). DOI: 10.1103/PhysRevB.84.214512</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N., Prischepa S.L., Cirillo C., Vecchione A., Attanasio C., Kupriyanov M.Yu., Aarts J. Multiple order parameter configurations in superconductor/ferromagnet multilayers. Phys. Rev. B. 2011;84:214512(1-10). DOI: 10.1103/PhysRevB.84.214512</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N. [States of the spin switches on the base of superconductor/ferromagnet multilayered structures]. Doklady BGUIR = Doklady BGUIR. 2013;78:40-46. (In Russ.)</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N. [States of the spin switches on the base of superconductor/ferromagnet multilayered structures]. Doklady BGUIR = Doklady BGUIR. 2013;78:40-46. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Kushnir V.N. [Triplet effect and the superconductivity states in the multilayered superconductor/ferromagnet structures]. Doklady BGUIR = Doklady BGUIR. 2016;97:18-23. (In Russ.)</mixed-citation><mixed-citation xml:lang="en">Kushnir V.N. [Triplet effect and the superconductivity states in the multilayered superconductor/ferromagnet structures]. Doklady BGUIR = Doklady BGUIR. 2016;97:18-23. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Usadel K. Generalized diffusion equation for superconducting alloy. Phys. Rev. Lett. 1970;25:507-509. DOI: 10.1103/PhysRevLett.25.507</mixed-citation><mixed-citation xml:lang="en">Usadel K. Generalized diffusion equation for superconducting alloy. Phys. Rev. Lett. 1970;25:507-509. DOI: 10.1103/PhysRevLett.25.507</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
