Long-range current-induced spin accumulation in chiral crystals

TL;DR

This paper uses advanced computational methods to quantify how chiral crystals generate and preserve spin accumulation from electric currents, revealing potential for long-range spin transport in spintronics.

Contribution

It introduces a DFT+PAOFLOW approach to quantify the collinear Rashba-Edelstein effect in chiral crystals, highlighting intrinsic protection of spin transport due to crystal symmetries.

Findings

Spin accumulation is protected by quasi-persistent spin helix.

Spin transport can be maintained over large distances.

Chiral materials enable chirality-dependent charge-to-spin conversion.

Abstract

Chiral materials, similarly to human hands, have distinguishable right-handed and left-handed enantiomers which may behave differently in response to external stimuli. Here, we use for the first time an approach based on the density functional theory (DFT)+PAOFLOW calculations to quantitatively estimate the so-called collinear Rashba-Edelstein effect (REE) that generates spin accumulation parallel to charge current and can manifest as chirality-dependent charge-to-spin conversion in chiral crystals. Importantly, we reveal that the spin accumulation induced in the bulk by an electric current is intrinsically protected by the quasi-persistent spin helix arising from the crystal symmetries present in chiral systems with the Weyl spin-orbit coupling. In contrast to conventional REE, spin transport can be preserved over large distances, in agreement with the recent observations for some chiral materials. This allows, for example, the generation of spin currents from spin accumulation, opening novel routes for the design of solid-state spintronics devices.