Current-induced Orbital and Spin Magnetizations in Crystals with Helical Structure

TL;DR

This paper theoretically demonstrates that electric currents induce orbital and spin magnetizations along the helical axis in crystals with a helical structure, with effects depending on the helix's handedness.

Contribution

It introduces a simple tight-binding model to predict current-induced magnetizations in helical crystals, generalizable to various such structures.

Findings

Magnetizations are opposite for right- and left-handed helices.

Induced spin magnetization arises from a radial spin texture on the Fermi surface.

Contrast with Rashba systems where magnetization is perpendicular to current.

Abstract

We theoretically show that in a crystal with a helical lattice structure, orbital and spin magnetizations along a helical axis are induced by an electric current along the helical axis. We propose a simple tight-binding model for calculations, and the results can be generalized to any helical crystals. The induced magnetizations are opposite for right-handed and left-handed helices. The current-induced spin magnetization along the helical axis comes from a radial spin texture on the Fermi surface. This is in sharp contrast to Rashba systems where the induced spin magnetization is perpendicular to the applied current.