Duration: 01.05.2017 – 30.04.2020, ARRS (J1-8138)

We propose a project to build a low-temperature time-resolved pump-probe scanning tunneling microscope (STM) for investigating the real-time femtosecond dynamics of elementary excitations in complex materials with atomic resolution. THz pulses will be used to excite plasmonic excitations in the metal STM tip, thus temporarily enhancing (gating) the tunneling current, and thus allowing us to probe the photoexcited dynamics on a subpicosecond timescale.

The microscope will be made to operate at temperatures down to 4.2 kelvin and will be implemented inside an Omicron 4-probe LT-STM system and an external THz source.

The technique will allow time-dynamics to be investigated in spatially nonhomogeneous systems for the first time, thus opening the way to address some longstanding fundamental problems in the dynamics of complex condensed matter systems. To demonstrate operation of our ultrafast STM (USTM) machine, we will perform exploratory experiments on a number of currently topical materials.