Phonon Angular Momentum Hall Effect

Authors:
Publisher website
Google Scholar
Abstract
Spin Hall effect is the transverse flow of the electron spin in response to external electric field. Similarly, temperature gradient in magnets can drive a transverse flow of the magnon spin, which provides a thermal alternative for spin manipulation. Recently, the phonon angular momentum (PAM), the angular momentum of atoms resulting from their orbital motion around their equilibrium positions, has garnered attention as a quantity analogous to the magnon spin. Here, we report that temperature gradient generally induces a transverse flow of PAM, which we term the phonon angular momentum Hall effect (PAMHE). The PAMHE arises whenever there are transverse and longitudinal acoustic phonons, and it is therefore ubiquitous in condensed matter systems. As a consequence of the PAMHE, PAM accumulates at the crystal edges. When the atoms in the crystal carry nonzero Born effective charge, the edge PAM induces edge magnetization, which can be observed through optical measurement.
Funding Information
  • National Research Foundation of Korea (0426-20200003)
  • Institute for Basic Science (IBS-R009-D1)
  • Army Research Laboratory (W911NF-18-1-0137)

This publication has 46 references indexed in Scilit: