Single particle and collective excitations in the one-dimensional charge density wave solid K0.3MoO3 probed in real time by femtosecond spectroscopy

TL;DR

This study uses femtosecond spectroscopy to investigate ultrafast single particle and collective excitations in the quasi-one-dimensional charge-density wave material K0.3MoO3, revealing temperature-dependent dynamics and mode behaviors.

Contribution

It provides the first detailed temperature-dependent analysis of non-equilibrium single particle excitations and their recombination in K0.3MoO3 using real-time femtosecond spectroscopy.

Findings

Observed temperature-dependent single particle excitation dynamics.

Detected amplitude mode reflectivity oscillations in real time.

Identified overdamped response related to phason mode relaxation.

Abstract

Ultrafast transient reflectivity changes caused by collective and single particle excitations in the quasi one-dimensional charge-density wave (CDW) semiconductor K0.3MoO3 are investigated with optical pump-probe spectroscopy. The temperature-dependence of non-equilibrium single particle excitations across the CDW gap and their recombination dynamics are reported for the first time. In addition, amplitude mode reflectivity oscillations are observed in real time. A T-dependent overdamped response is also observed which is attributed to relaxation of the phason mode.