[11a-W933-1~11] 6.6 Probe Microscopy

[11a-W933-3] Optical-pump-probe STM: Delay-time modulation with less intensity modulation

〇Osamu Takeuchi¹, Zi-Han Wang¹, Hiroyuki Mogi¹, Cheul Hyun Yoon¹, Atsushi Taninaka¹, Shoji Yoshida¹, Hidemi Shigekawa¹ (1.Univ. of Tsukuba)

Keywords:pump probe, scanning tunneling microscopy

Optical-pump-probe STM is known as a femtosecond-time-resolved STM. In this presentation, we explain the conventional delay-time modulation method that has been used in OPP-STM measurements accompanies finite optical intensity modulation at the same frequency with delay-time modulation, which can cause fake signals. A new delay-time modulation scheme is invented to reduce the intensity modulation and it is experimentally proved that the new scheme can indeed suppress the fake signal by applying it to a WSe₂ sample.