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arXiv · 1810.07515

Strain induced superconducting pair-density-wave states in graphene

Feng Xu·Po-Hao Chou·Chung-Hou Chung·Ting-Kuo Lee·Chung-Yu Mou
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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.

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Feng Xu, Po-Hao Chou, Chung-Hou Chung, Ting-Kuo Lee, Chung-Yu Mou. 2018-10-17. Strain induced superconducting pair-density-wave states in graphene. https://doi.org/10.1103/physrevb.98.205103

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