Size dependence of electron spin dephasing in InGaAs quantum dots

Journal Article · Mon Mar 02 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4914084· OSTI ID:22412769

Huang, Y. Q.; Puttisong, Y.; Buyanova, I. A.; Chen, W. M. ^[1]; Yang, X. J.; Subagyo, A.; Sueoka, K.; Murayama, A. ^[2]

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1. Department of Physics, Chemistry and Biology, Linköping University, S-581 83 Linköping (Sweden)
2. Graduate School of Information Science and Technology, Hokkaido University, Kita 14, Nishi 9, Kita-ku, Sapporo 060-0814 (Japan)

We investigate ensemble electron spin dephasing in self-assembled InGaAs/GaAs quantum dots (QDs) of different lateral sizes by employing optical Hanle measurements. Using low excitation power, we are able to obtain a spin dephasing time T{sub 2}{sup *} (in the order of ns) of the resident electron after recombination of negative trions in the QDs. We show that T{sub 2}{sup *} is determined by the hyperfine field arising from the frozen fluctuation of nuclear spins, which scales with the size of QDs following the Merkulov-Efros-Rosen model. This scaling no longer holds in large QDs, most likely due to a breakdown in the lateral electron confinement.

• OSTI ID: 22412769
• Journal Information: Applied Physics Letters, Vol. 106, Issue 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
CONFINEMENT
ELECTRONS
EXCITATION
FLUCTUATIONS
GALLIUM ARSENIDES
INDIUM ARSENIDES
INTERFACES
QUANTUM DOTS
RECOMBINATION
SPIN