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arXiv · 1406.2684

Spin-flip Raman scattering of the $\Gamma$-X mixed exciton in indirect band-gap (In,Al)As/AlAs quantum dots

J. Debus·T. S. Shamirzaev·D. Dunker·V. F. Sapega·E. L. Ivchenko·D. R. Yakovlev·A. I. Toropov·M. Bayer
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Abstract

The band structure of type-I (In,Al)As/AlAs quantum dots with band gap energy exceeding 1.63 eV is indirect in momentum space, leading to long-lived exciton states with potential applications in quantum information. Optical access to these excitons is provided by mixing of the $\Gamma$- and X-conduction band valleys, from which control of their spin states can be gained. This access is used here for studying the exciton spin-level structure by resonant spin-flip Raman scattering, allowing us to accurately measure the anisotropic hole and isotropic electron $g$ factors. The spin-flip mechanisms for the indirect exciton and its constituents as well as the underlying optical selection rules are determined. The spin-flip intensity is a reliable measure of the strength of $\Gamma$-X-valley mixing, as evidenced by both experiment and theory.

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J. Debus, T. S. Shamirzaev, D. Dunker, V. F. Sapega, E. L. Ivchenko, D. R. Yakovlev, A. I. Toropov, M. Bayer. 2014-06-09. Spin-flip Raman scattering of the $\Gamma$-X mixed exciton in indirect band-gap (In,Al)As/AlAs quantum dots. https://doi.org/10.1103/physrevb.90.125431

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