Spin in Uniform Gravity, Hidden Momentum, and the Anomalous Hall Effect

TL;DR

This paper reviews the absence of the spin Hall effect in uniform gravity and contrasts it with the anomalous spin Hall effect in ferromagnetic materials, highlighting key differences despite similar Hamiltonian forms.

Contribution

It clarifies the conditions under which the spin Hall effect is absent in gravitational fields versus ferromagnetic systems, providing insight into their fundamental differences.

Findings

No spin Hall effect in uniform gravitational fields.

Differences between gravitational and ferromagnetic spin Hall effects.

Analysis of Hamiltonian similarities and differences.

Abstract

We review the recent discussion of the absence of spin Hall effect in a uniform gravitational field, pointing out differences from the anomalous spin Hall effect in ferromagnetics despite a similar form of the Hamiltonian.