Electrically Controllable Chiral Phonons in Ferroelectric Materials

TL;DR

This paper demonstrates that external electric fields can reversibly control the chirality of phonons in ferroelectric materials, enabling switchable phononic phenomena for potential thermal and information device applications.

Contribution

It introduces a method to electrically control chiral phonons in ferroelectric materials, demonstrated through first-principles calculations on In$_2$Se$_3$, which was not previously possible.

Findings

Electric field reverses phonon chirality in ferroelectrics.

Reversal induces phenomena like magnetization and phonon Hall effect.

Potential for designing switchable phononic devices.

Abstract

Chiral phonons have attracted increasing attention, as they play important roles in many different systems and processes. However, a method to control phonon chirality by external fields is still lacking. Here, we propose that in displacement-type ferroelectric materials, an external electric field can reverse the chirality of chiral phonons via ferroelectric switching. Using first-principles calculations, we demonstrate this point in the well known two-dimensional ferroelectric In$_2$Se$_3$. This reversal may lead to a number of electrically switchable phenomena, such as chiral phonon induced magnetization, phonon Hall effect, and possible interface phonon modes at ferroelectric domain boundaries. Our work offers a new way to control chiral phonons, which could be useful for the design of thermal or information devices based on them.