Researchers at the RUN have directly observed how a spin-orbit-split energy level of an isolated chalcogen vacancy in a Moiré-distorted WSe2 monolayer adiabatically shifts upon excitation of a drum-like phonon mode. Establishing time-resolved lightwave scanning tunneling spectroscopy with atomic, sub-ps and 10 meV-scale resolution, ultrafast snapshots of the phonon mode and the local density of states reveal shifts of the defect level by up to 40 meV. This novel technique enables the local observation and control of ultrafast dynamics of energy levels paving the way for a deeper understanding of a plethora of phenomena – electron-phonon coupling, transient phase transitions and moiré exciton trapping, to name a few. DFT calculations by members of the RUN underpin the experimental results.
The results have been published in Nature Photonics (Coverstory).
© Brad Baxley, PtW
