Flat bands and multi-state memory devices from chiral domain wall superlattices in magnetic Weyl semimetals

TL;DR

This paper introduces a new analog memory device based on magnetic Weyl semimetal domain walls, demonstrating conductance modulation and flat band formation that enable multi-state memory and chirality-polarized current generation.

Contribution

It predicts tunable flat bands and conductance modulation in magnetic Weyl semimetals with domain walls, proposing a novel multi-state memory device and spintronic applications.

Findings

Tunable flat bands in helically-magnetized regions.

Multiple conductance states enabled by domain wall nucleation.

Generation of chirality-polarized currents in Bloch devices.

Abstract

We propose a novel analog memory device utilizing the gigantic magnetic Weyl semimetal (MWSM) domain wall (DW) magnetoresistance. We predict that the nucleation of domain walls between contacts will strongly modulate the conductance and allow for multiple memory states, which has been long sought-after for use in magnetic random access memories or memristive neuromorphic computing platforms. We motivate this conductance modulation by analyzing the electronic structure of the helically-magnetized MWSM Hamiltonian, and report tunable flat bands in the direction of transport in a helically-magnetized region of the sample for Bloch and Neel-type domain walls via the onset of a local axial Landau level spectrum within the bulk of the superlattice. We show that Bloch devices also provide means for the generation of chirality-polarized currents, which provides a path towards nanoelectronic utilization of chirality as a new degree of freedom in spintronics.