Gigantic tunneling magnetoresistance in magnetic Weyl semimetal tunnel junctions

TL;DR

This paper demonstrates that magnetic Weyl semimetal tunnel junctions exhibit an extraordinarily high tunneling magnetoresistance ratio due to chirality-magnetization locking, surpassing traditional spin filtering effects, with potential for advanced spintronic applications.

Contribution

It introduces a novel mechanism for giant TMR in Weyl semimetal junctions based on chirality-magnetization locking, independent of spin filtering.

Findings

TMR ratio can reach up to 10^4% with realistic fluctuations.

Conductance shows non-monotonic dependence on magnetization misalignment.

Chirality-magnetization locking enhances TMR beyond conventional ferromagnets.

Abstract

We investigate the tunneling magnetoresistance in magnetic tunnel junctions (MTJs) comprised of Weyl semimetal contacts. We show that chirality-magnetization locking leads to a gigantic tunneling magnetoresistance ratio, an effect that does not rely on spin filtering by the tunnel barrier. Our results indicate that the conductance in the anti-parallel configuration is more sensitive to magnetization fluctuations than in MTJs with normal ferromagnets, and predicts a TMR as large as 10^4 % when realistic magnetization fluctuations are accounted for. In addition, we show that the Fermi arc states give rise to a non-monotonic dependence of conductance on the misalignment angle between the magnetizations of the two contacts.