Ultrafast Decoherence of Charge Density Waves in K$_{0.3}$MoO$_{3}$

TL;DR

This study investigates the ultrafast dynamics of charge density waves in K$_{0.3}$MoO$_{3}$, revealing rapid phase inversion and disorder formation within a picosecond, emphasizing disorder's role in coherent control.

Contribution

The paper provides experimental evidence and numerical modeling of ultrafast CDW phase inversion and disorder dynamics in K$_{0.3}$MoO$_{3}$ after optical excitation.

Findings

Transient CDW phase inversion near the surface

Disorder develops in less than one picosecond

Numerical simulations replicate experimental observations

Abstract

Recent works have suggested that transient suppression of a charge density wave (CDW) by an ultra-short excitation can lead to an inversion of the CDW phase. We experimentally investigate the dynamics of the CDW in K$_{0.3}$MoO$_{3}$ by time resolved x-ray diffraction after excitation with optical pulses. Our results indicate a transient inversion of the CDW phase close to the surface that evolves into a highly disordered state in less than one picosecond. Numerical simulations solving the Ginzburg-Landau equation including disorder from strong pinning defects reproduce our main observations. Our findings highlight the critical role of disorder in schemes for coherent control in condensed matter systems.