Ultrafast Nonlinear Spectroscopy for Probing Valley Excitons in Layered Transition Metal Dichalcogenides

Project: Research

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Ultrafast optical spectroscopy is of great importance for understanding the laws of electron motion in 2D semiconductor materials. However, the limited temporal resolution of conventional techniques leads to the bottleneck for accessing the information within short timescales. In this project, we aim to tackle this bottleneck by proposing a new nonlinear spectroscopic technique, to capture the fast dynamics of quantum degrees of freedom of electrons in layered transition metal dichalcogenides (TMDs), with greatly enhanced resolutions. The new nonlinear spectroscopic probe is a hybrid scheme consisting of signal designs with laser pulse shaping and photonic nanocavities, which can offer extra knobs for controlling the electron dynamics and the resolutions. In particular, we will develop the pump-probe and photon correlation spectroscopies for valley exciton relaxation in TMDs, and will implement the ultrafast spectroscopic technique in experiments of cavity-coupled TMDs. The nanocavities will not only improve the signal-to-noise ratio of emission, but will also enable the band-gap engineering for controlling the exciton dynamics. We believe this proposal will open a new avenue for unveiling the mystery of ultrafast physics in 2D materials. 


Project number7020045
Grant typeSIRG
Effective start/end date1/05/22 → …