Strain induced superconducting pair-density-wave states in graphene

ORAL

Abstract

Graphene is known to be non-superconducting. However, surprising superconductivity is recently discovered in a flat-band in a twisted bi-layer graphene. Here we show that superconductivity can be more easily realized in topological flat-bands induced by strain in graphene through periodic ripples. Specifically, it is shown that by including correlation effects, the chiral d-wave superconductivity can be stabilized under strain even for slightly doped graphene. The chiral d-wave superconductivity generally coexists with charge density waves (CDW) and pair density waves (PDW) of the same period. Remarkably, a pure PDW state with doubled period that coexists with the CDW state is found to emerge at a finite temperature region under reasonable strain strength. The emergent PDW state is shown to be superconducting with non-vanishing superfluid density, and it realizes the long searched superconducting states with non-vanishing center of mass momentum for Cooper pairs.

*We acknowledge support from the Ministry of Science and Technology (MoST), Taiwan. In addition, we also acknowledge support from Center for Quantum Technology, TCECM, and Academia Sinica Research Program on Nanoscience and Nanotechnology, Taiwan.

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Presenters

  • Chung-Yu Mou

    • Department of physics, National Tsing-Hua University
    • Departmeny of Physics, National Tsing Hua University, Hsinchu, Taiwan
    • Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

Authors

  • Chung-Yu Mou

    • Department of physics, National Tsing-Hua University
    • Departmeny of Physics, National Tsing Hua University, Hsinchu, Taiwan
    • Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

  • Feng Xu

    • School of Physics and Telecommunication Engineering, Shaanxi University of technology, Hanzhong, China

  • Chung-Hou Chung

    • Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan, R.O.C.
    • National Chiao Tung University
    • Department of Eletrophysics, National Chiao Tung University
    • Department of Electrophysics, National Chiao Tung University
    • Electrophysics Department, National Chiao-Tung University, Hsinchu, Taiwan
    • Electrophysics Department, National Chiao-Tung University, Taiwan

  • Ting-Kuo Lee

    • Institute of Physics, Academia Sinica
    • Institute of Physics, Academia Sinica, Taiwan
    • Institute of physics, Academia Sinica