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arXiv · 1901.08850

Berry phase of phonons and thermal Hall effect in nonmagnetic insulators

Takuma Saito·Kou Misaki·Hiroaki Ishizuka·Naoto Nagaosa
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Abstract

A mechanism for phonon Hall effect (PHE) in non-magnetic insulators under an external magnetic field is theoretically studied. PHE is known in (para)magnetic compounds, where the magnetic moments and spin-orbit interaction play an essential role. In sharp contrast, we here show that a non-zero Berry curvature of acoustic phonons is induced by an external magnetic field due to the correction to the adiabatic Born-Oppenheimer approximation. This results in the finite thermal Hall conductivity $κ_H$ in nonmagnetic band insulators. Our estimate of $κ_H$ for a simple model gives $κ_H \sim 1.0\times 10^{-5} $[W/Km] at $ B=10 $[T] and $ T=150 $[K].

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Takuma Saito, Kou Misaki, Hiroaki Ishizuka, Naoto Nagaosa. 2019-01-28. Berry phase of phonons and thermal Hall effect in nonmagnetic insulators. https://doi.org/10.1103/physrevlett.123.255901

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