Dynamics of non-adiabatic single electron pumping
Zusammenfassung der Projektergebnisse
Semiconductor quantum dots allow to examine and to exploit transport of individual electrons. Recently quantum dots with strongly time varying couplings to the leads have become a subject of intense research, motivated by their potential use as on-demand single electron sources for e.g. electron optics experiments or as candidates for the realization of a quantum current standard based on high frequency clocked single charge transport. Within the project both the dynamic physical processes governing the single electron transport in this strongly driven systems have been studied and different applications of the hereby realized clocked single electron sources have been examined: A newly developed measurement of the full counting statistics of the single electron transfer by a sophisticated single electron detection scheme allowed to clarify the mechanism of the electron capture process. This will allow to develop single electron pumps with improved fidelity. Feedback effects have been studied for in series connected driven quantum dots which are connected by a small mesoscopic electron reservoir. This proofed the feasibility of stable operation of multiple clocked single electron sources in series which will be used to realize intrinsic real time error detection and correction in a single electron based realization of the base unit Ampere. In an integrated circuit of a clocked single electron pump with a quantized Hall resistor the generation of a quantized voltage depending only on fundamental constants and the driving frequency was shown. Combining this device with a Josephson junction would allow for an important consistency test for the fundaments of electrical quantum metrology. The partitioning of clocked electron pairs, generated by a triggered single electron source, has been examined by a cross correlation technique. The results open the route towards quantum state tomography of clocked electron pairs and towards the generation of spatially separated spin entangled electron pairs.
Projektbezogene Publikationen (Auswahl)
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Partitioning of on-demand electron pairs
Niels Ubbelohde, Frank Hohls, Vyacheslavs Kashcheyevs, Timo Wagner, Lukas Fricke, Bernd Kästner, Klaus Pierz, Hans W. Schumacher and Rolf J. Haug
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Synchronized single electron emission from dynamical quantum dots, Applied Physics Letters 97, 252104 (2010)
P. Mirovsky, B. Kaestner, C. Leicht, A. C. Welker, T. Weimann, K. Pierz, and H. W. Schumacher
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A quantized current source with mesoscopic feedback, Phys. Rev. B 83, 193306 (2011)
Lukas Fricke, Frank Hohls, Niels Ubbelohde, Bernd Kaestner, Vyacheslavs Kashcheyevs, Christoph Leicht, Philipp Mirovsky, Klaus Pierz, Hans W. Schumacher, Rolf J. Haug
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Constructive role of non-adiabaticity for quantized charge pumping AIP conference proceedings 1399, 345 (2011)
B. Kaestner, P. Mirovsky, C. Leicht, V. Kashcheyevs, E. V. Kurganova, U. Zeitler, K. Pierz, H. W. Schumacher
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A semiconductor quantized voltage source, Phys. Rev. Lett. 109, 056802 (2012)
Frank Hohls, Armin C. Welker, Christoph Leicht, Lukas Fricke, Bernd Kaestner, Philipp Mirovsky, André Müller, Klaus Pierz, Uwe Siegner, and Hans Werner Schumacher
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Characterization of a GHz non-adiabatic single-electron pump using a cryogenic current comparator, CPEM 2012 digest pp. 706-707 (2012)
B. Kaestner, C. Leicht, F. Hohls, M. Götz, D. Drung, K. Pierz, F.J. Ahlers, H.W. Schumacher
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Counting statistics for electron capture in a dynamic quantum dot, Phys. Rev. Lett. 110, 126803 (2013)
Lukas Fricke, Michael Wulf, Bernd Kaestner, Vyacheslavs Kashcheyevs, Janis Timoshenko, Pavel Nazarov, Frank Hohls, Philipp Mirovsky, Brigitte Mackrodt, Ralf Dolata, Thomas Weimann, Klaus Pierz, and Hans W. Schumacher
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Spin-dependent shot noise enhancement in a quantum dot, Physical Review B, 88, 041304(R) (2013)
Niels Ubbelohde, Christian Fricke, Frank Hohls and Rolf J. Haug
