Ultrafast all-optical manipulation of the charge-density wave in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>VTe</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
Manuel Tuniz, Davide Soranzio, Davide Bidoggia, Denny Puntel, Wibke Bronsch, Steven L. Johnson, Maria Peressi, F. Parmigiani, Federico Cilento
Abstract
The charge-density-wave (CDW) phase in the layered transition-metal dichalcogenide ${\mathrm{VTe}}_{2}$ 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, we investigate the broadband time-resolved reflectivity variations caused by collective and single-particle excitations in the CDW ground state of ${\mathrm{VTe}}_{2}$. With the aid of density functional perturbation theory simulations we unveil 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, gaining insights into the coupling between these two collective excitations and demonstrating a more efficient way to perturb the CDW phase in ${\mathrm{VTe}}_{2}$.