Lightwave valleytronics in a monolayer of tungsten diselenide

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F. Langer, C. P. Schmid, S. Schlauderer, M. Gmitra, J. Fabian, P. Nagler, C. Schüller, T. Korn, P. G. Hawkins,
J. T. Steiner, U. Huttner, S. W. Koch, M. Kira, R. Huber

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Nature 557, 76–80 (2018)

Future quantum information technologies need robust and quickly switchable states to be used as quantum bits. Such a qubit may be provided by a spin-like quantity called valley pseudospin, describing the position of electrons in either of two distinct energetic valleys in momentum space. In a collaboration with the groups of Mackillo Kira (University of Michigan), Stephan Koch (University of Marburg), Christian Schüller and Tobias Korn (University of Regensburg) and Jaroslav Fabian (University of Regensburg) we have shown how the valley pseudospin of a monolayer of tungsten diselenide can be switched using an intense lightwave to accelerate the electrons from one valley to the other faster than a single oscillation of light. This opens the door to room-temperature quantum signal processing at optical clock rates. The results are reported in Nature 557, 76-80 (2018)

http://www.uni-regensburg.de/pressearchiv/pressemitteilung/869531.html

https://www.nature.com/articles/s41586-018-0013-6

https://news.engin.umich.edu/2018/05/light-could-make-semiconductor-computers-a-million-times-faster-or-even-go-quantum/