Transverse Peierls Transition

TL;DR

This paper introduces new symmetry-breaking phases triggered by softening transverse acoustic phonons via electron-phonon interactions, predicting exotic effects in topological semimetals under magnetic fields.

Contribution

It proposes a novel class of phases, shear and self-twisting waves, arising from phonon mode softening, and links them to topological semimetals in quantum limit conditions.

Findings

Prediction of shear and self-twisting wave phases.

Identification of topological semimetals as candidates for realization.

Potential observation of exotic effects like 3D quantum Hall and chiral phonons.

Abstract

In the present paper, we have discussed a new type of spontaneous symmetry breaking phases caused by the softening of the transverse acoustic phonon modes through the electron phonon coupling. These new phases include the shear density wave and self-twisting wave, which are caused by the softening of linearly and circularly polarized acoustic phonon modes, respectively. We propose that two of the topological semimetal systems in the quantum limit, where the electrons only occupy the lowest Landau bands under external magnetic field, will be the perfect systems to realize these new phases. Exotic physical effects will be induced in these new phases, including the 3D quantum Hall effect, chiral standing acoustic wave, magneto-acoustic effects and chiral phonon correction to Einstein-de Hass effect.