# Orbital Edelstein effect as a condensed-matter analog of solenoid

## TL;DR

This paper explores how chiral crystals can generate orbital magnetization through current, drawing an analogy to a solenoid, and introduces a dimensionless parameter to quantify this effect, highlighting potential for large orbital magnetization in Weyl semimetals.

## Contribution

It proposes a theoretical framework linking current-induced orbital magnetization in chiral crystals to a solenoid analogy and defines a dimensionless parameter to quantify the effect.

## Key findings

- Weyl semimetals can exhibit large orbital magnetization.
- The dimensionless parameter exceeds classical solenoid values in some materials.
- Designing band structures can enhance orbital magnetization effects.

## Abstract

We theoretically study current-induced orbital magnetization in a chiral crystal. This phenomenon is an orbital version of the Edelstein effect. We propose an analogy between the current-induced orbital magnetization and an Amp\`ere field in a solenoid in classical electrodynamics. In order to quantify this effect, we define a dimensionless parameter from the response coefficient relating a current density with an orbital magnetization. This dimensionless parameter can be regarded as a number of turns within a unit cell when the crystal is regarded as a solenoid, and it represents how "chiral" the crystal is. By focusing on the dimensionless parameter, one can design band structure which realizes induction of large orbital magnetization. In particular, a Weyl semimetal with all the Weyl nodes close to the Fermi energy can have a large value of this dimensionless parameter, which can exceed that of a classical solenoid.