Evidence for a Peierls phase-transition in a three-dimensional multiple charge-density waves solid

TL;DR

This study demonstrates a Peierls phase transition in a three-dimensional charge-density wave solid by photoinducing melting of charge order and confirming the Peierls mechanism through combined experimental and ab initio analysis.

Contribution

It provides the first direct evidence of a Peierls origin for multiple charge-density waves in a three-dimensional material, advancing understanding of phase transitions in complex solids.

Findings

Charge-density wave persists despite high electronic temperature.

Lattice distortion triggers the phase transition.

First ab initio confirmation of Peierls mechanism in 3D.

Abstract

The effect of dimensionality on materials properties has become strikingly evident with the recent discovery of graphene. Charge ordering phenomena can be induced in one dimension by periodic distortions of a material's crystal structure, termed Peierls ordering transition. Charge-density waves can also be induced in solids by strong Coulomb repulsion between carriers, and at the extreme limit, Wigner predicted that crystallization itself can be induced in an electrons gas in free space close to the absolute zero of temperature. Similar phenomena are observed also in higher dimensions, but the microscopic description of the corresponding phase transition is often controversial, and remains an open field of research for fundamental physics. Here, we photoinduce the melting of the charge ordering in a complex three-dimensional solid and monitor the consequent charge redistribution by probing the optical response over a broad spectral range with ultrashort laser pulses. Although the photoinduced electronic temperature far exceeds the critical value, the charge-density wave is preserved until the lattice is sufficiently distorted to induce the phase transition. Combining this result with it ab initio} electronic structure calculations, we identified the Peierls origin of multiple charge-density waves in a three-dimensional system for the first time.