skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Size dependence of electron spin dephasing in InGaAs quantum dots

Abstract

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.

Authors:
; ; ;  [1]; ; ; ;  [2]
  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)
Publication Date:
OSTI Identifier:
22412769
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 9; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; CONFINEMENT; ELECTRONS; EXCITATION; FLUCTUATIONS; GALLIUM ARSENIDES; INDIUM ARSENIDES; INTERFACES; QUANTUM DOTS; RECOMBINATION; SPIN

Citation Formats

Huang, Y. Q., Puttisong, Y., Buyanova, I. A., Chen, W. M., Yang, X. J., Subagyo, A., Sueoka, K., and Murayama, A. Size dependence of electron spin dephasing in InGaAs quantum dots. United States: N. p., 2015. Web. doi:10.1063/1.4914084.
Huang, Y. Q., Puttisong, Y., Buyanova, I. A., Chen, W. M., Yang, X. J., Subagyo, A., Sueoka, K., & Murayama, A. Size dependence of electron spin dephasing in InGaAs quantum dots. United States. doi:10.1063/1.4914084.
Huang, Y. Q., Puttisong, Y., Buyanova, I. A., Chen, W. M., Yang, X. J., Subagyo, A., Sueoka, K., and Murayama, A. Mon . "Size dependence of electron spin dephasing in InGaAs quantum dots". United States. doi:10.1063/1.4914084.
@article{osti_22412769,
title = {Size dependence of electron spin dephasing in InGaAs quantum dots},
author = {Huang, Y. Q. and Puttisong, Y. and Buyanova, I. A. and Chen, W. M. and Yang, X. J. and Subagyo, A. and Sueoka, K. and Murayama, A.},
abstractNote = {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.},
doi = {10.1063/1.4914084},
journal = {Applied Physics Letters},
number = 9,
volume = 106,
place = {United States},
year = {Mon Mar 02 00:00:00 EST 2015},
month = {Mon Mar 02 00:00:00 EST 2015}
}