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arXiv · 0909.1592

Spin noise of electrons and holes in self-assembled quantum dots

S. A. Crooker·J. Brandt·C. Sandfort·A. Greilich·D. R. Yakovlev·D. Reuter·A. D. Wieck·M. Bayer
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Abstract

We measure the frequency spectra of random spin fluctuations, or "spin noise", in ensembles of (In,Ga)As/GaAs quantum dots (QDs) at low temperatures. We employ a spin noise spectrometer based on a sensitive optical Faraday rotation magnetometer that is coupled to a digitizer and field-programmable gate array, to measure and average noise spectra from 0-1 GHz continuously in real time with sub-nanoradian/root-Hz sensitivity. Both electron and hole spin fluctuations generate distinct noise peaks, whose shift and broadening with magnetic field directly reveal their g-factors and dephasing rates within the ensemble. A large, energy-dependent anisotropy of the in-plane hole g-factor is clearly exposed, reflecting systematic variations in the average QD confinement potential.

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S. A. Crooker, J. Brandt, C. Sandfort, A. Greilich, D. R. Yakovlev, D. Reuter, A. D. Wieck, M. Bayer. 2009-09-08. Spin noise of electrons and holes in self-assembled quantum dots. https://doi.org/10.1103/physrevlett.104.036601

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