Chiral Vortical Effect For An Arbitrary Spin

TL;DR

This paper demonstrates that the chiral vortical effect (CVE), previously studied for fermions, is a universal phenomenon applicable to massless particles of any spin, with potential experimental observations in quantum optics.

Contribution

It generalizes the chiral kinetic theory to arbitrary spin particles and clarifies discrepancies in existing formulations of CVE in rotating systems.

Findings

CVE applies to massless particles of any spin.

Derived semi-classical equations of motion in rotating frames.

Potential observation of higher-spin CVE in quantum optics experiments.

Abstract

The spin Hall effect of light attracted enormous attention in the literature due to the ongoing progress in developing of new optically active materials and metamaterials with non-trivial spin-orbit interaction. Recently, it was shown that rotating fermionic systems with relativistic massless spectrum may exhibit a 3d analogue of the spin Hall current -- the chiral vortical effect (CVE). Here we show that CVE is a general feature of massless particles with an arbitrary spin. We derive the semi-classical equations of motion in rotating frame from the first principles and show how by coordinate transformation in the phase space it can be brought to the intuitive form proposed in [1]. Our finding clarifies the superficial discrepancies in different formulations of the chiral kinetic theory for rotating systems. We then generalize the chiral kinetic theory, originally introduced for fermions, to an arbitrary spin and study chirality current in a general rotating chiral medium. We stress that the higher-spin realizations of CVE can be in principle observed in various setups including table-top experiments on quantum optics.