Spin-motive force and orbital-motive force: from magnon BEC to chiral Weyl superfluids

TL;DR

This paper explores the extension of spin-motive and orbital-motive forces from metallic ferromagnets to magnon Bose-Einstein condensates and chiral superfluid 3He-A, highlighting topological and chiral effects.

Contribution

It introduces a unified framework for spin-motive and orbital-motive forces across different quantum systems, emphasizing topological and chiral phenomena.

Findings

Extension of spin-motive force to magnon BEC with phase-coherent magnetization precession

Identification of two contributions to orbital-motive force in superfluid 3He-A

Connection between chiral Weyl fermions, Weyl points, and chiral anomaly phenomena

Abstract

Spin-motive geometric force acting on electrons in metallic ferromagnets is extended to spin-motive force in magnon BEC, which is represented by phase-coherent precession of magnetization, and to the orbital-motive force in superfluid 3He-A. In 3He-A there are two contributions to the orbital-motive force. One of them comes from the chiral nature of this liquid. Another one originates from chiral Weyl fermions living in the vicinity of the topologically protected Weyl points, and is related to the phenomenon of chiral anomaly.