Presentation Information
[9p-E206-1][JSAP-Optica Joint Symposia Invited Talk] Ultrafast Dynamics in Two-Dimensional Materials Probed by Terahertz Scanning Tunneling Microscopy
〇Shoji Yoshida1 (1.Univ. of Tsukuba)
Keywords:
Scanning Probe Microscopy,2D materials,Ultrafast dynamics
Two-dimensional (2D) materials such as transition metal dichalcogenides exhibit unique optical properties, including tightly bound excitons, yet their electronic and optical responses are governed by nanoscale heterogeneities that are averaged out in diffraction-limited far-field measurements. Probing their ultrafast dynamics thus demands atomic-scale spatial and femtosecond temporal resolution. Time-resolved scanning tunneling microscopy based on terahertz pulses (THz-STM) meets this need: a sub-cycle THz pulse transiently drives the tunneling current, capturing the instantaneous local density of states and its temporal evolution. In this talk, I will review recent advances in THz-STM and its application to ultrafast dynamics in 2D materials. As one representative example, I will present measurements of exciton dynamics in a WSe2/MoS2 heterostructure, where the THz-induced current yields the local exciton lifetime, and discuss the broader prospects of THz-STM.