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arXiv · 2412.19894

Chirality-induced pseudo-magnetic fields, flat bands and enhancement of superconductivity

Zhiyu Dong·Leonid Levitov·Patrick A. Lee
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Abstract

Systems in which exchange interactions couple carrier spins to a spin texture with a net chirality exhibit a spin-dependent Aharonov-Bohm effect, where the geometric gauge field and pseudo-magnetic field have opposite signs for carriers with opposite spins. As a result, Cooper pairs see a net zero vector potential and superconducting pairing is not hindered by pair-breaking effects. This allows superconductivity to occur even when the geometric field induces quantized Landau levels. We identify the dominant pairing order as an s-wave pair density wave of an FFLO type. Flat Landau levels can significantly enhance superconducting $T_c$, favoring superconductivity over competing orders. This exotic paired state features tell-tale signatures such as flat bands of Bogoliubov-deGennes quasiparticles, manifest through Landau level-like resonances in the quasiparticle density of states.

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Zhiyu Dong, Leonid Levitov, Patrick A. Lee. 2024-12-27. Chirality-induced pseudo-magnetic fields, flat bands and enhancement of superconductivity. https://arxiv.org/abs/2412.19894

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