{"title":"Unconventional superconductivity from electronic dipole fluctuations","authors":"Grgur Palle, Jörg Schmalian","doi":"10.1103/physrevb.110.104516","DOIUrl":null,"url":null,"abstract":"We study electron-electron Coulomb interactions in electronic systems whose Fermi surfaces possess a finite electric dipole density. Although there is no net dipole moment, we show that electric monopole-dipole interactions can become sufficiently strong in quasi-2D Dirac metals with spin-orbit coupling to induce unconventional odd-parity superconductivity, similar to the Balian-Werthamer state of <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mmultiscripts><mi mathvariant=\"normal\">He</mi><mprescripts></mprescripts><none></none><mn>3</mn></mmultiscripts><mo>−</mo><mi mathvariant=\"normal\">B</mi></mrow></math>. Hence, materials with spin-orbit-induced band inversion, such as the doped topological insulators <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Se</mi><mn>3</mn></msub></mrow></math>, <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><msub><mi>Bi</mi><mn>2</mn></msub><msub><mi>Te</mi><mn>3</mn></msub></mrow></math>, and <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>SnTe</mi></math>, are natural candidate materials where our theory could be relevant. We discuss the conditions for an electric dipole density to appear on the Fermi surface and develop the formalism to describe its coupling to the plasmon field, which mediates the Coulomb interaction. A mechanism for the enhancement of dipolar coupling is then provided for quasi-2D Dirac systems. Within a large-<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>N</mi></math> renormalization group treatment, we show that the out-of-plane (<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>z</mi></math>-axis) dipole coupling is marginally relevant, in contrast to the monopole coupling, which is marginally irrelevant. For physically realistic parameters, we find that dipole fluctuations can get sufficiently enhanced to result in Cooper pairing. In addition, we establish that the proposed pairing glue is directly measurable in the <math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>z</mi></math>-axis optical conductivity.","PeriodicalId":20082,"journal":{"name":"Physical Review B","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-09-20","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.110.104516","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}
引用次数: 0
Abstract
We study electron-electron Coulomb interactions in electronic systems whose Fermi surfaces possess a finite electric dipole density. Although there is no net dipole moment, we show that electric monopole-dipole interactions can become sufficiently strong in quasi-2D Dirac metals with spin-orbit coupling to induce unconventional odd-parity superconductivity, similar to the Balian-Werthamer state of . Hence, materials with spin-orbit-induced band inversion, such as the doped topological insulators , , and , are natural candidate materials where our theory could be relevant. We discuss the conditions for an electric dipole density to appear on the Fermi surface and develop the formalism to describe its coupling to the plasmon field, which mediates the Coulomb interaction. A mechanism for the enhancement of dipolar coupling is then provided for quasi-2D Dirac systems. Within a large- renormalization group treatment, we show that the out-of-plane (-axis) dipole coupling is marginally relevant, in contrast to the monopole coupling, which is marginally irrelevant. For physically realistic parameters, we find that dipole fluctuations can get sufficiently enhanced to result in Cooper pairing. In addition, we establish that the proposed pairing glue is directly measurable in the -axis optical conductivity.
期刊介绍:
Physical Review B (PRB) is the world’s largest dedicated physics journal, publishing approximately 100 new, high-quality papers each week. The most highly cited journal in condensed matter physics, PRB provides outstanding depth and breadth of coverage, combined with unrivaled context and background for ongoing research by scientists worldwide.
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