Orbital Edelstein effect as a condensed-matter analog of solenoid

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 Ampere 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. [1] T. Yoda, T. Yokoyama, and S. Murakami, Sci. Rep. 5, 12024 (2015). [2] T. Yoda, T. Yokoyama, and S. Murakami, arXiv:1706.07702.