Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 19: Quantum dots and wires: Transport properties

HL 19.10: Talk

Tuesday, March 13, 2018, 12:00–12:15, A 151

Quantum stochastic resonance in driven single-electron tunneling — •Timo Wagner¹, Johannes C. Bayer¹, Eddy P. Rugeramigiabo¹, Peter Hänggi², and Rolf. J. Haug¹ — ¹Institut für Festkörperphysik, Leibniz Universität Hannover, Germany — ²Institut für Physik, Universität Augsburg, Germany

Ambient noise is generically considered to be harmful for an error-free signal detection. However, a certain level of noise can actually have a constructive influence and boost an otherwise subthreshold signal, known as stochastic resonance (SR) [1]. All reported SR systems thus far exhibit either thermal noise or need an additional external noise generator. For quantum systems, theory predicted that intrinsic quantum randomness may give rise to stochastic resonance as well [2,3]. Here, we experimentally evidence quantum stochatic resonance (QSR) in the periodically driven charging of single-electrons in a quantum dot. By extracting the counting statistics [4,5], we demonstrate that the synchronization of the tunneling events with the periodic driving runs across an optimum, no matter whether the external frequency or the internal shot-noise level are tuned. The tunneling events were temporally resolved, using single-electron charge detection [5,6].

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[2] R. Löfstedt, et al. Phys. Rev. Lett. 72, 1947-1950 (1994).

[3] M. Grifoni & P. Hänggi, Phys. Rev. Lett. 76, 1611-1614 (1996).

[4] P. Talkner, et al. New J. Phys. 7, 14 (2005).

[5] S. Gustavsson, et al. Phys. Rev. Lett. 96, 076605 (2006).

[6] T. Wagner, et al. Nature Nanotech. 12, 218-222 (2017).