Anomalous spectral dependence of optical polarization and its impact on spin detection in InGaAs/GaAs quantum dots

Journal Article · Mon Sep 29 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4897306· OSTI ID:22350800

Puttisong, Y.; Huang, Y. Q.; 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 show that circularly polarized emission light from InGaAs/GaAs quantum dot (QD) ensembles under optical spin injection from an adjacent GaAs layer can switch its helicity depending on emission wavelengths and optical excitation density. We attribute this anomalous behavior to simultaneous contributions from both positive and negative trions and a lower number of photo-excited holes than electrons being injected into the QDs due to trapping of holes at ionized acceptors and a lower hole mobility. Our results call for caution in reading out electron spin polarization by optical polarization of the QD ensembles and also provide a guideline in improving efficiency of spin light emitting devices that utilize QDs.

• OSTI ID: 22350800
• Journal Information: Applied Physics Letters, Vol. 105, Issue 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DETECTION
EMISSION
EXCITATION
GALLIUM ARSENIDES
HOLE MOBILITY
HOLES
INDIUM ARSENIDES
INJECTION
LAYERS
LIGHT EMITTING DIODES
POLARIZATION
QUANTUM DOTS
READOUT SYSTEMS
SPIN
SPIN ORIENTATION
TRAPPING
VISIBLE RADIATION
WAVELENGTHS