Pair density wave and reentrant superconducting tendencies originating from valley polarization

Zhaoyu Han; Steven A. Kivelson

doi:10.1103/physrevb.105.l100509

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arXiv · 2112.03278

Pair density wave and reentrant superconducting tendencies originating from valley polarization

Zhaoyu Han·Steven A. Kivelson

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Abstract

We investigate superconducting pairing tendencies of a two-dimensional electron fluid with both valley and spin degrees of freedom, both without and in the presence of an in-plane magnetic field. We present suggestive theoretical arguments that spontaneous valley polarization can lead to exotic singlet superconducting tendencies, including pair-density-wave order at zero field and re-entrant superconductivity at high field. We also find a reduced magnetic response in the polarized valley, which allows a finite violation of the Pauli limit. These results are obtained by a mean-field approach to a generalized $t$-$J$ model on a triangular lattice and in the dilute limit. Phenomenological similarities to results of recent magic-angle twisted trilayer graphene experiments are noted.

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Zhaoyu Han, Steven A. Kivelson. 2021-12-06. Pair density wave and reentrant superconducting tendencies originating from valley polarization. https://doi.org/10.1103/physrevb.105.l100509

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