{"title":"NbSe2/MoS2 Ising 超导中的电子-声子耦合、临界温度和间隙","authors":"Shubham Patel, Soumyasree Jena, A. Taraphder","doi":"10.1103/physrevb.110.014507","DOIUrl":null,"url":null,"abstract":"Utilizing Migdal-Eliashberg theory of superconductivity within the first-principles calculations, we work out the role of electron-phonon coupling (EPC) and anisotropic superconducting properties of a recently discovered [Baidya <i>et al.</i>, <span>Phys. Rev. B</span> <b>104</b>, 174510 (2021)] 2D van der Waals heterostructure comprising a single layer of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoS</mi><mn>2</mn></msub></math> and few layers of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. We find strong EPC and a softening of phonon modes in the lowest acoustic branch. While the single <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoS</mi><mn>2</mn></msub></math> layer does not actively contribute to the EPC, it significantly elevates the superconducting critical temperature (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi>c</mi></msub></math>) compared to monolayer <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. This is attributed to the degradation of the charge-density wave by the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>MoS</mi><mn>2</mn></msub></math> layer. Notably, we observe a two-gap superconductivity in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>NbSe</mi><mn>2</mn></msub><mo>/</mo><msub><mi>MoS</mi><mn>2</mn></msub></mrow></math> and extend our study to three layers of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. A reduction in <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi>c</mi></msub></math> with increasing thickness of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>NbSe</mi><mn>2</mn></msub></math> is observed. Incorporation of spin-orbit coupling (SOC) suggests a possible mechanism for Ising superconductivity. We find that SOC reduces EPC while <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi>c</mi></msub></math> is suppressed concomitantly by about 5K, leading to a closer estimate of the experimental <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mi>T</mi><mi>c</mi></msub></math>.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Electron-phonon coupling, critical temperatures, and gaps in NbSe2/MoS2 Ising superconductors\",\"authors\":\"Shubham Patel, Soumyasree Jena, A. Taraphder\",\"doi\":\"10.1103/physrevb.110.014507\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Utilizing Migdal-Eliashberg theory of superconductivity within the first-principles calculations, we work out the role of electron-phonon coupling (EPC) and anisotropic superconducting properties of a recently discovered [Baidya <i>et al.</i>, <span>Phys. Rev. B</span> <b>104</b>, 174510 (2021)] 2D van der Waals heterostructure comprising a single layer of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>MoS</mi><mn>2</mn></msub></math> and few layers of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. We find strong EPC and a softening of phonon modes in the lowest acoustic branch. While the single <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>MoS</mi><mn>2</mn></msub></math> layer does not actively contribute to the EPC, it significantly elevates the superconducting critical temperature (<math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>T</mi><mi>c</mi></msub></math>) compared to monolayer <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. This is attributed to the degradation of the charge-density wave by the <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>MoS</mi><mn>2</mn></msub></math> layer. Notably, we observe a two-gap superconductivity in <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><mrow><msub><mi>NbSe</mi><mn>2</mn></msub><mo>/</mo><msub><mi>MoS</mi><mn>2</mn></msub></mrow></math> and extend our study to three layers of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>NbSe</mi><mn>2</mn></msub></math>. A reduction in <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>T</mi><mi>c</mi></msub></math> with increasing thickness of <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>NbSe</mi><mn>2</mn></msub></math> is observed. Incorporation of spin-orbit coupling (SOC) suggests a possible mechanism for Ising superconductivity. We find that SOC reduces EPC while <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>T</mi><mi>c</mi></msub></math> is suppressed concomitantly by about 5K, leading to a closer estimate of the experimental <math xmlns=\\\"http://www.w3.org/1998/Math/MathML\\\"><msub><mi>T</mi><mi>c</mi></msub></math>.\",\"PeriodicalId\":20082,\"journal\":{\"name\":\"Physical Review B\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.7000,\"publicationDate\":\"2024-07-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Review B\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1103/physrevb.110.014507\",\"RegionNum\":2,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"Physics and Astronomy\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review B","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevb.110.014507","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
Electron-phonon coupling, critical temperatures, and gaps in NbSe2/MoS2 Ising superconductors
Utilizing Migdal-Eliashberg theory of superconductivity within the first-principles calculations, we work out the role of electron-phonon coupling (EPC) and anisotropic superconducting properties of a recently discovered [Baidya et al., Phys. Rev. B104, 174510 (2021)] 2D van der Waals heterostructure comprising a single layer of and few layers of . We find strong EPC and a softening of phonon modes in the lowest acoustic branch. While the single layer does not actively contribute to the EPC, it significantly elevates the superconducting critical temperature () compared to monolayer . This is attributed to the degradation of the charge-density wave by the layer. Notably, we observe a two-gap superconductivity in and extend our study to three layers of . A reduction in with increasing thickness of is observed. Incorporation of spin-orbit coupling (SOC) suggests a possible mechanism for Ising superconductivity. We find that SOC reduces EPC while is suppressed concomitantly by about 5K, leading to a closer estimate of the experimental .
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