Theory of “Emergence of excitonic superfluid at topological-insulator surfaces”

ORAL

Abstract

We study the BCS condensation of excitons on topological-insulator surfaces. With presence of a screened Coulomb interaction between excited electrons and holes, the BCS excitons can be formed with predicted transition temperature up to 40K. The thermal fluctuation is found to disturb the long-range order by creating vortex excitations. It lowers the mean-field estimation of the transition temperature and drives the transition into the Kosterlitz-Thouless type. The BCS condensation of excitons forms ground state with quantum coherence that leads to the experimentally observed long-range transport of photocurrent. We also discuss possible generation of the topological p+ip excitonic insulators at topological-insulator surfaces.

*This work was supported by National Science Foundation Grant DMR-1838532 and DMR-1710737. S.Y.S was supported by National Science Foundation Grant DMR-1411336. This research used the Molecular Foundry and the Advanced Light Source, which are US Department of Energy Office of Science User Facilities under contract no. DE-AC02-05CH11231. H.F. acknowledges the U.S. National Science Foundation Research Experiences for Undergraduates (REU) program under Grant No. PHY-1560482.

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Presenters

  • Rui Wang

    • Shanghai Jiao Tong University

Authors

  • Rui Wang

    • Shanghai Jiao Tong University

  • Yasen Hou

    • University of California, Davis
    • University of california, Davis

  • Rui Xiao

    • University of California, Davis
    • University of california, Davis

  • Luke McClintock

    • University of California, Davis
    • University of california, Davis

  • Henry Clark Travaglini

    • University of California, Davis
    • University of california, Davis

  • John Paulus Francia

    • University of California, Davis
    • University of california, Davis

  • Harry Fetsch

    • Harvey Mudd College

  • Onur Erten

    • Arizona State University
    • Rutgers University, New Brunswick
    • Department of Physics, Arizona State University

  • Sergey Savrasov

    • Physics, UC Davis
    • University of California, Davis
    • University of california, Davis

  • Baigeng Wang

    • Nanjing University

  • Antonio Rossi

    • University of California, Davis
    • University of california, Davis

  • Inna Vishik

    • University of California, Davis
    • University of california, Davis
    • Physics, University of California, Davis

  • Eli Rotenberg

    • Advanced Light Source, E.O. Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
    • Advanced Light Source, Lawrence Berkeley National Laboratory
    • ALS, Lawrence National Berkeley Laboratory
    • Advanced Light Source, Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Advanced Light Source (ALS), E. O. Lawrence Berkeley National Laboratory, USA
    • Advanced Light Source, E. O. Lawrence Berkeley National Laboratory

  • Dong Yu

    • University of California, Davis
    • University of california, Davis