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HL: Fachverband Halbleiterphysik
HL 37: Quantum Dots and Wires: Optical Properties I (mainly InGaAs Dots)
HL 37.3: Vortrag
Dienstag, 27. März 2012, 11:15–11:30, ER 164
Spin Noise of Holes in Quantum Dots — •Ramin Dahbashi1, Jens Hübner1, Fabian Berski1, Julia Wiegand1, Xavier Marie2, Klaus Pierz3, Hans Werner Schumacher3, and Michael Oestreich1 — 1Institute for Solid State Physics, Leibniz Universität Hannover, Appelstr. 2, D-30167 Hannover, Germany — 2Université de Toulouse; INSA, UPS, CNRS; LPCNO, 135 avenue de Rangueil, F-31077 Toulouse, France — 3Physikalisch Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany
We measure the spin dephasing of holes localized in self-assembled (InGa)As quantum dots by spin noise spectroscopy [1]. The localized holes show a distinct hyperfine interaction with the nuclear spin bath despite the p-type symmetry of the valence band states. The experiments reveal a short spin relaxation time of 27 ns and a second, long spin relaxation time which exceeds the first one by more than one order of magnitude. The two times are attributed to heavy hole spins aligned perpendicular and parallel to the stochastic nuclear magnetic field. Intensity dependent measurements and numerical simulations reveal despite low laser intensity and large detuning that the long relaxation time is still obscured by light absorption.
[1] Dahbashi et al., Measurement of heavy-hole spin dephasing in (InGa)As quantum dots, arXiv:1109.0610v1 [cond-mat.mes-hall] (2011, Submitted to APL).
[2] Müller et al.,Semiconductor spin noise spectroscopy: Fundamentals, accomplishments, and challenges, Physica E 43, 569 (2010).