Strong magnetic field induces superconductivity in Weyl semi - metal

TL;DR

This paper develops a microscopic theory showing that magnetic fields can induce superconductivity in Weyl semimetals by pairing on Landau levels, with experimental signatures observed in magnetoresistance reductions.

Contribution

It introduces a theory predicting magnetic-field-induced superconductivity in Weyl semimetals via Landau level pairing, a phenomenon easier to detect than in conventional metals.

Findings

Superconductivity can be induced at specific magnetic fields in Weyl semimetals.

Superconductivity manifests as a reduction in magnetoresistivity.

Experimental observations in materials like Cd3As2 and ZrTe5 support the theory.

Abstract

Microscopic theory of the normal-to-superconductor coexistence line of a 2D two-band Weyl superconductor subjected to magnetic field is constructed. It is shown that a Weyl semi-metal that is nonsuperconducting or having a small critical temperature $T_{c}$ at zero field, might become a superconductor at higher temperature when the magnetic field is tuned to a series of quantized values $H_{n}$. The pairing occurs on Landau levels. It is argued that the phenomenon is much easier detectable in Weyl semi - metals than in parabolic band metals since the quantum limit already has been approaches in several Weyl materials.. An experimental signature of the superconductivity on Landau levels is the reduction of magnetoresistivity. This has already been observed in $Cd_{3}As_{2}$ and several other compounds. The novel kind of quantum oscillations of magnetoresistance detected in $ZrTe_{5}$ is discussed along these lines.