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arXiv · 2203.04471

Topological Quantum Phase Transitions in Metallic Shiba Lattices

Ning Dai·Kai Li·Yan-Bin Yang·Yong Xu
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Abstract

Shiba bands formed by overlapping Yu-Shiba-Rusinov subgap states in magnetic impurities on a superconductor play an important role in topological superconductors. Here, we theoretically demonstrate the existence of a new type of Shiba bands (dubbed topological Shiba metal) on a magnetically doped $s$-wave superconducting surface with Rashba spin-orbit coupling in the presence of a weak in-plane magnetic field. Such topological gapless Shiba bands develop from gapped Shiba bands through Lifshitz phase transitions accompanied by second-order quantum phase transitions for the intrinsic thermal Hall conductance. We also find a mechanism in Shiba lattices that protects the first-order quantum phase transitions for the intrinsic thermal Hall conductance. Due to the long-range hopping in Shiba lattices, the topological Shiba metal exhibits intrinsic thermal Hall conductance with large nonquantized values. As a consequence, there emerge a large number of second-order quantum phase transitions.

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Ning Dai, Kai Li, Yan-Bin Yang, Yong Xu. 2022-03-09. Topological Quantum Phase Transitions in Metallic Shiba Lattices. https://doi.org/10.1103/physrevb.106.115409

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