Chiral Vortical and Gyrotropic Effects in Weyl Semimetals

The chiral anomaly is the source of various interesting phenomena for chiral fermions, and especially in Weyl semimetals which contain chiral fermions as low energy excitations. For example, a magnetic field leads to a longitudinal current flow in the absence of electric fields, well known as the chiral magnetic effect. Since the Coriolis force behaves like a Lorentz force in many ways, one expects an axial current induced by rotation for chiral fermions. This is known as the chiral vortical effect. This effect has attracted a lot of attention in nuclear physics for its possible consequences for heavy ion collisions [1]. In this work, we theoretically explore the possibility of the chiral vortical effect in Weyl semimetals. In particular, we argue that naively rotating a Weyl semimetal is not the correct way to induce the chiral vortical effect. Instead, one must rotate the chiral fluid of electrons relative to the background lattice. The latter can be achieved via an electric field with a non-zero curl, and is otherwise known as the gyrotropic effect.

Reference:
[1] D.E. Kharzeev, J. Liao, S.A. Voloshin, and G. Wang, Prog. Part. Nucl. Phys., 88:1-28 (2016)