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HL: Fachverband Halbleiterphysik
HL 21: Quantum Nanophotonics in Solid State Systems
HL 21.2: Vortrag
Dienstag, 2. April 2019, 14:15–14:30, H33
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
An exciton in a single quantum dot is an attractive implementation of a qubit, since it can be Rabi-flopped or coherently manipulated with pulsed laser fields. Robust methods of preparation have been demonstrated by the application of polarization tailored pulses [1] or chirped laser pulses, resulting in rapid adiabatic passage (RAP) [2,3]. Here we use unchirped laser pulses and an ultrafast transient Stark shift of the exciton energy to prepare an inversion via RAP. We use self-assembled InGaAs QDs embedded in a low capacitance Schottky-photodiode. An ultrafast BiCMOS chip that is closely connected to the photodiode generates transient Stark shifts as fast as 3.6 µeV/ps. It operates at low temperature and is synchronized to the laser excitation. By detecting the occupancy of the QD via photocurrent detection, we are able to observe the transition from the unchirped Rabi scenario to a RAP 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)