Karl Franzens University Graz
Graz University of Technology
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Karl Franzens University Graz | Graz University of Technology | |
Momentum-Space Movies of Electrons at Interfaces and in 2D Semiconductors Time-resolved photoemission combines femtosecond pump-probe techniques with angle-resolved photoelectron spectroscopy (ARPES). New opportunities for this powerful technique arise in combination with THz excitation on one hand and ultrashort XUV probe pulses on the other hand. I will present three examples and explain how THz-ARPES can be used to measure current transport in the Dirac surface state of a three-dimensional topological insulator in a contact-free fashion and with femtosecond time-resolution [1, Figure], discuss how time-resolved photoemission orbital tomography can access ultrafast electron transfer processes at metal/organic contacts [2], and finally reveal the formation of dark excitons in a two-dimensional semiconductor a few 10 fs after optical excitation [3]. |