Optical orientation and alignment of excitons in direct and indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment

RAUTERT, Janina, Timur S. SHAMIRZAEV, S. V. NEKRASOV, Dmitri R. YAKOVLEV, Petr KLENOVSKÝ, Yu. G. KUSRAYEV and Manfred BAYER. Optical orientation and alignment of excitons in direct and indirect band gap (In,Al)As/AlAs quantum dots with type-I band alignment. Online. Physical Review B. American Physical Society, 2019, vol. 99, No 19, p. 195411-195420. ISSN 2469-9950. Available from: https://dx.doi.org/10.1103/PhysRevB.99.195411. [citováno 2024-04-24]

Basic information

• Original name: 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, Janina (276 Germany), Timur S. SHAMIRZAEV (643 Russian Federation), S. V. NEKRASOV (643 Russian Federation), Dmitri R. YAKOVLEV (643 Russian Federation), Petr KLENOVSKÝ (203 Czech Republic, guarantor, belonging to the institution), Yu. G. KUSRAYEV (643 Russian Federation) and Manfred BAYER (276 Germany)
• Edition: Physical Review B, American Physical Society, 2019, 2469-9950.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10302 Condensed matter physics
• Country of publisher: United States of America
• Confidentiality degree: is not subject to a state or trade secret
• WWW: URL
• Impact factor: Impact factor: 3.575
• RIV identification code: RIV/00216224:14310/19:00109629
• Organization unit: Faculty of Science
• Doi: http://dx.doi.org/10.1103/PhysRevB.99.195411
• UT WoS: 000467383900003
• Keywords in English: (InAl)As/AlAs;kvantove tecky;rekombinacni procesy
• Tags: International impact, Reviewed

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 ?-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.

Links

• 8C18001, research and development project: Name: CMOS Compatible Single Photon Sources based on SiGe Quantum Dots (Acronym: CUSPIDOR)

Investor: Ministry of Education, Youth and Sports of the CR, QUANTERA