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HL: Fachverband Halbleiterphysik
HL 32: Quantum dots and wires: Optical properties II
HL 32.9: Vortrag
Mittwoch, 14. März 2018, 17:15–17:30, A 151
Quantum dot rapid adiabatic passage by ultrafast Stark tuning — Amlan Mukherjee1, Alex Widhalm1, •Björn Jonas1, Sebastian Krehs1, Nand Lal Sharma1, Peter Kölling2, Andreas Thiede2, Jens Förstner2, Dirk Reuter1, and Artur Zrenner1 — 1Physics Department, University of Paderborn, Warburger Straße 100, Paderborn 33098, Germany — 2Department of Electrical Engineering, University of Paderborn, Warburger Straße 100, Paderborn 33098, Germany
For the case of pulsed laser fields and in the absence of decoherence, an exciton in a single QD represents a qubit, which can be tuned by electric fields. Robust state preparation has been achieved so far by using polarization tailored pulses [1] or chirped pulses for the realization of a rapid adiabatic passage (RAP) [2,3].
Here we demonstrate state preparation by RAP, using fast transient Stark shift of the exciton energy. Our system is based on self-assembled InGaAs QDs embedded in a low capacitance Schottky-photodiode. The photodiode is closely connected to a SiGe:C BiCMOS chip, which delivers transients as fast as 4.7 mV/ps at low temperature. The ps electric transient is synchronized to the optical pulse. The occupancy of the QD can be read out by photocurrent detection. We are able to observe the transition from an un-chirped Rabi scenario to a clear RAP signature when the electric chirp is applied.
[1] D. Mantei et al., Sci. Rep. 5, S. 10313 (2015)
[2] Yanwen Wu et al., PRL 106, 067401 (2011)
[3] C.M. Simon et al., PRL 106, 166801 (2011)