Ferroelectricity-driven phonon Berry curvature and non-linear phonon Hall transports

TL;DR

This paper demonstrates how ferroelectricity in a monolayer material induces a switchable non-linear phonon Hall effect through phonon Berry curvature, enabling controllable topological phononic transport and memory applications.

Contribution

It reveals a new ferroelectricity-phonon coupling mechanism that induces a switchable non-linear phonon Hall effect via phonon Berry curvature in 2D materials.

Findings

Ferroelectricity induces phonon Berry curvature in SnS monolayer.

Switchable non-linear phonon Hall effect demonstrated.

Potential for topological phononic devices and memory applications.

Abstract

Berry curvature (BC) governs topological phases of matter and generates anomalous transport. When a magnetic field is applied, phonons can acquire BC indirectly through spin-lattice coupling, leading to a linear phonon Hall effect. Here, we show that polar lattice distortion directly couples to a phonon BC dipole, which causes a switchable non-linear phonon Hall effect. In a SnS monolayer, the in-plane ferroelectricity induces a phonon BC and leads to the phononic version of the non-volatile BC memory effect. As a new type of ferroelectricity-phonon coupling, the phonon Rashba effect emerges and opens a mass-gap in tilted Weyl phonon modes, resulting in a large phonon BC dipole. Furthermore, our ab initio non-equilibrium molecular dynamics simulations reveal that non-linear phonon Hall transport occurs in a controllable manner via ferroelectric switching. The ferroelectricity-driven phonon BC and corresponding non-linear phonon transports provide a novel scheme for constructing topological phononic transport/memory devices.