Correlating Critical Dynamics to an Onset of a “Hidden” Metastable Phase in 1T-TaS2

1T-TaS2 is a van der Waals transition metal dichalcogenide material with unique ‘Star of David’ charge density wave (CDW) states at thermal equilibrium. Numerous studies have characterized the various CDW phases in 1T-TaS2 through observables such as resistivity, optical reflectivity, and scanning tunnelling microscopy, but experiments to study the recently discovered ‘hidden’ metastable CDW state have been less revealing. In particular, the temperature-dependent switching probability and the lifetime of the hidden phase lacks a fundamental explanation. Therefore, we propose to use x-ray photon correlation spectroscopy to directly measure equilibrium dynamics of the commensurate CDW phase to investigate the electronic environment favorable in opening the nonequilibrium pathway to the hidden phase. We aim to find the critical temperature and the corresponding dynamic environment within the commesurate phase that allows for the onset of the hidden phase.