Abstract
Topological insulators with the time reversal symmetry broken exhibit strong magnetoelectric and magneto-optic effects. While these effects are well understood in or near equilibrium, nonequilibrium physics is richer yet less explored. We consider a topological insulator thin film, weakly coupled to a ferromagnet, out of thermal equilibrium with a cold environment (quantum electrodynamics vacuum). We show that the heat flow to the environment is strongly circularly polarized, thus carrying away angular momentum and exerting a purely fluctuation-driven torque on the topological insulator film. Utilizing the Keldysh framework, we investigate the universal nonequilibrium response of the TI to the temperature difference with the environment. Finally, we argue that experimental observation of this effect is within reach.
- Received 8 January 2019
- Revised 9 May 2019
DOI:https://doi.org/10.1103/PhysRevLett.123.055901
© 2019 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Topological Insulators Do the Twist
Published 1 August 2019
Theorists uncover a new magnetomechanical effect in topological insulators that are hotter than their environment.
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