Dresden 2017 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 69: Quantum Dots: Transport Properties I

HL 69.6: Talk

Thursday, March 23, 2017, 11:15–11:30, POT 151

Optimal feedback control of a single-electron transistor. — •Timo Wagner¹, Philipp Strasberg², Johannes C. Bayer¹, Eddy P. Rugeramigabo¹, Tobias Brandes², and Rolf J. Haug¹ — ¹Institut für Festkörperphysik, Leibniz Universität, Appelstr. 2, D-30167 Hannover, Germany — ²Institut für Theoretische Physik, TU Berlin, Hardenbergstr. 36, D-10623 Berlin, Germany

Recently we reported the strong suppression of shot noise in a closed-loop feedback controlled single-electron transistor [1]. The implemented feedback loop compensates the time-dependent fluctuations between the single electron-tunneling events, leading to a highly accurate and stable tunneling current [1,2]. Our technique is analog to the generation of squeezed light in quantum optics, using in-loop photo detection [3]. Here we investigate the optimal feedback response, achieving the maximum suppression of shot-noise. For the optimal response the saturation value of the second cumulant of the full counting statistics [4] is found to be given by the electron target number. Astonishingly the feedback works even for target numbers much smaller than one.

[1] T. Wagner, et al. Nature Nanotech. (doi:10.1038/nnano.2016.225)

[2] T. Brandes, Phys. Rev. Lett. 105, 06060 (2010)

[3] S. Machida, Y. Yamamoto, Opt. Commun. 57, 290 (1986)

[4] S. Gustavson, et al., Surf. Sci. Rep. 64, 191 (2009)