# Optical control of vibrational coherence triggered by an ultrafast phase transition

## TL;DR

This paper demonstrates optical control over vibrational coherence in a charge-density-wave material using ultrafast phase transition techniques, revealing extended coherence times and potential for manipulating lattice states.

## Contribution

It introduces a multi-pulse scheme to extend vibrational coherence lifetime by re-exciting electronic states during an ultrafast phase transition.

## Key findings

- Extended vibrational coherence lifetime through re-excitation.
- Control over damping pathways of coherent lattice oscillations.
- Potential to manipulate lattice states via electronic population control.

## Abstract

Femtosecond time-resolved x-ray diffraction is employed to study the dynamics of the periodic lattice distortion (PLD) associated with the charge-density-wave (CDW) in K0.3MoO3. Using a multi-pulse scheme we show the ability to extend the lifetime of coherent oscillations of the PLD about the undistorted structure through re-excitation of the electronic states. This suggests that it is possible to enter a regime where the symmetry of the potential energy landscape corresponds to the high symmetry phase but the scattering pathways that lead to the damping of coherent dynamics are still controllable by altering the electronic state population. The demonstrated control over the coherence time offers new routes for manipulation of coherent lattice states.