Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/101764
Title: Optical orientation and alignment of excitons in direct and indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment
Authors: Rautert, J.
Shamirzaev, T. S.
Nekrasov, S. V.
Yakovlev, D. R.
Klenovský, P.
Kusrayev, Y. G.
Bayer, M.
Issue Date: 2019
Publisher: American Physical Society
Citation: Optical orientation and alignment of excitons in direct and indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment / J. Rautert, T. S. Shamirzaev, S. V. Nekrasov, et al. — DOI 10.1103/PhysRevB.99.195411 // Physical Review B. — 2019. — Vol. 99. — Iss. 19. — 195411.
Abstract: The spin structure and spin dynamics of excitons in an ensemble of (In,Al)As/AlAs quantum dots (QDs) with type-I band alignment, containing both direct and indirect band gap dots, are studied. Time-resolved and spectral selective techniques are used to distinguish between the direct and indirect QDs. The exciton fine structure is studied by means of optical alignment and optical orientation techniques in magnetic fields applied in the Faraday or Voigt geometries. A drastic difference in emission polarization is found for the excitons in the direct QDs involving a Γ-valley electron and the excitons in the indirect QDs contributed by an X-valley electron. We show that in the direct QDs the exciton spin dynamics is controlled by the anisotropic exchange splitting, while in the indirect QDs it is determined by the hyperfine interaction with nuclear field fluctuations. The anisotropic exchange splitting is determined for the direct QD excitons and compared with model calculations. © 2019 American Physical Society.
Keywords: ANISOTROPY
ENERGY GAP
EXCITONS
NANOCRYSTALS
SPIN FLUCTUATIONS
ANISOTROPIC EXCHANGE SPLITTING
EXCITON FINE STRUCTURE
EXCITON SPIN DYNAMICS
HYPERFINE INTERACTIONS
MODEL CALCULATIONS
OPTICAL ALIGNMENTS
OPTICAL ORIENTATION
TYPE I BAND ALIGNMENTS
SEMICONDUCTOR QUANTUM DOTS
URI: http://hdl.handle.net/10995/101764
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 85065469100
PURE ID: 9819328
017f7e76-11e8-45c0-91b0-52dcf52593b1
ISSN: 24699950
DOI: 10.1103/PhysRevB.99.195411
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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