Ultrafast all-optical manipulation of the charge-density-wave in VTe$_{2}$

TL;DR

This study uses broadband time-resolved optical spectroscopy to investigate and manipulate the charge-density wave phase in VTe₂, revealing two collective modes and demonstrating ultrafast control of the CDW state.

Contribution

It introduces a double-pulse excitation scheme to efficiently manipulate the collective modes of the CDW phase in VTe₂, advancing ultrafast control techniques.

Findings

Identification of two collective amplitude modes in VTe₂'s CDW phase

Demonstration of manipulation of CDW modes using double-pulse excitation

Ultrafast optical spectroscopy reveals dynamics of CDW in VTe₂

Abstract

The charge-density wave (CDW) phase in the layered transition-metal dichalcogenide VTe$_{2}$ is strongly coupled to the band inversion involving vanadium and tellurium orbitals. In particular, this coupling leads to a selective disappearance of the Dirac-type states that characterize the normal phase, when the CDW phase sets in. Here, by means of broadband time-resolved optical spectroscopy (TR-OS), we investigate the ultrafast reflectivity changes caused by collective and single particle excitations in the CDW ground state of VTe$_{2}$. Remarkably, our measurements show the presence of two collective (amplitude) modes of the CDW ground state. By applying a double-pulse excitation scheme, we show the possibility to manipulate these modes, demonstrating a more efficient way to control and perturb the CDW phase in VTe$_{2}$.