Eur. Phys. J. Special Topics 222, 1161-1175 (2013)
https://doi.org/10.1140/epjst/e2013-01912-2

Review

Optical pump-probe scanning tunneling microscopy for probing ultrafast dynamics on the nanoscale

Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Japan

^a e-mail: http://dora.bk.tsukuba.ac.jp

Received: 18 March 2013
Revised: 12 May 2013
Published online: 15 July 2013

Abstract

The development of a method for exploring the ultrafast transient dynamics in small organized structures with high spatial resolution is expected to be a basis for further advances in current science and technology. Recently, we have developed a new microscopy technique by combining scanning tunneling microscopy (STM) with ultrashort-pulse laser technology, which enables the visualization of ultrafast carrier dynamics even on the single-atomic level. A nonequilibrium carrier distribution is generated using ultrashort laser pulses and its relaxation processes are probed by STM using the optical pump-probe method realized in STM by the pulse-picking technique. In this paper, the fundamentals of the new microscopy technique are overviewed.