Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 19: Quantum dots and wires: Transport properties

HL 19.8: Vortrag

Dienstag, 13. März 2018, 11:30–11:45, A 151

Charge Reconfiguration in Quantum Dot Arrays — •Johannes C. Bayer, Timo Wagner, Eddy P. Rugeramigabo, and Rolf J. Haug — Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover, Germany

The quantum dot device is based on a two-dimensional electron gas formed in a GaAs/AlGaAs heterostructure. Metallic Schottky gates are used to laterally define arrays of up to four quantum dots in series. Two quantum point contacts (QPCs) in the vicinity act as sensitive charge detectors, allowing the real-time detection of electrons tunneling through the system [1].

Isolating a double quantum dot from the electron reservoirs has been shown to significantly simplify the stability diagram and at the same time increase the tunability of the system [2]. While transport vanishes for isolated quantum dots, charge reconfigurations inside the array are still observable in the detector signal. Our experimental studies on isolated double, triple and quadruple quantum dot arrays are complemented by model simulations which enable us to identify the different transitions occurring in our systems, including higher order tunneling in triple and quadruple quantum dots.

References

[1] T. Wagner, P. Strasberg, J. C. Bayer, et. al., Nat. Nanotech. 12, 218-222 (2017).

[2] B. Bertrand, H. Flentje, S. Takada, et. al., Phys. Rev. Lett. 115, 096801 (2015).