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arXiv · 2101.00192

Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of strained graphene

Feng Xu·Lei Zhang·Liyun Jiang·Wendeng Huang·Chung-Yu Mou
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Abstract

We obtain the superfluid weight and Berezinskii-Kosterlitz-Thouless (BKT) transition temperature for highly unconventional superconducting states with the coexistence of chiral d-wave superconductivity, charge density waves and pair density waves in the strained graphene. Our results show that the strain-induced flat bands can promote the superconducting transition temperature approximately $50\%$ compared to that of the original doped graphene, which suggests that the flat-band superconductivity is a potential route to get superconductivity with higher critical temperatures. In particular, we obtain the superfluid weight for the pure superconducting pair-density-wave states from which the deduced superconducting transition temperature is shown to be much lower than the gap-opening temperature of the pair density wave, which is helpful to understand the phenomenon of the pseudogap state in high-$T_c$ cuprate superconductors. Finally, we show that the BKT transition temperature versus doping for strained graphene exhibits a dome-like shape and it depends linearly on the spin-spin interaction strength.

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Feng Xu, Lei Zhang, Liyun Jiang, Wendeng Huang, Chung-Yu Mou. 2021-01-01. Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of strained graphene. https://arxiv.org/abs/2101.00192

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