Dresden 2011 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 70: Quantum Dots and Wires: Theory
HL 70.13: Vortrag
Donnerstag, 17. März 2011, 13:30–13:45, POT 151
Influence of LO-phonon collisions on robust adiabatic passage in semiconductor quantum dots — •Kolja Schuh1, Michael Lorke2, and Frank Jahnke1 — 1Institute for Theoretical Physics, University of Bremen, Germany — 2DTU Fotonik, Department of Photonics Enginering, Technical University of Denmark
While Rabi-oscillations can be used to invert a system with a resonant optical pulse, the inversion is very sensitive to pulse parameters like frequency and pulse area. An inversion can also be achieved via an adiabatic passage using a chirped optical pulse. In contrast to a resonant pulse, this inversion is robust over a large parameter scale.
The influence of LO-phonon collisions on robust adiabatic passage in self-assembled semiconductor quantum-dot (QD) systems is analyzed within a quantum-kinetic many-body theory including non-Markovian effects and quasi-particle properties [1]. For QD states the effective LO-phonon coupling is enhanced leading to pronounced dephasing as well as fast carrier scattering processes even in low polar semiconductors.
Numerical results are presented for different InGaAs QD systems including wetting layer contributions. While inversion can be achieved in QD systems with slow dephasing by a pulse length of several ps, this is not possible for systems with fast dephasing and scattering. Achieving inversion in such dots requires a tradeoff between keeping the adiabatic regime and minimizing dephasing and carrier scattering by short and strongly chirped pulses.
[1] K. Schuh et al., APL 94, 201108 (2009).