Spin dynamics in the second subband of a quasitwo-dimensional system studied in a single-barrier heterostructure by time-resolved Kerr rotation

F. Zhang; H. Z. Zheng; Y. Ji; J. Liu; G. R. Li

doi:10.1209/0295-5075/83/47007

All issues

Volume 83 / No 4 (August 2008)

EPL, 83 4 (2008) 47007

Abstract

Issue		EPL Volume 83, Number 4, August 2008


Article Number		47007
Number of page(s)		5
Section		Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI		https://doi.org/10.1209/0295-5075/83/47007
Published online		06 August 2008

EPL, 83 (2008) 47007

Spin dynamics in the second subband of a quasi $\hbox{--}$ two-dimensional system studied in a single-barrier heterostructure by time-resolved Kerr rotation

F. Zhang, H. Z. Zheng, Y. Ji, J. Liu and G. R. Li

State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences - P.O. Box 912, Beijing 100083, China

Corresponding author: hzzheng@red.semi.ac.cn

Received: 27 March 2008
Accepted: 25 June 2008

Abstract

Spin dynamics in the first and second subbands have been examined simultaneously by time resolved Kerr rotation in a single-barrier heterostructure of a 500 nm thick GaAs absorption layer. By scanning the wavelengths of the probe and pump beams towards the short wavelength in the zero magnetic field, the spin coherent time $T_{2}^{1*}$ in the $1{\rm st}$ subband E₁ decreases in accordance with the D'yakonov-Perel' (DP) spin decoherence mechanism. Meanwhile, the spin coherence time $T_{2}^{2*}$ in the $2{\rm nd}$ subband E₂ remains very low at wavelengths longer than 810 nm, and then is dramatically enhanced afterwards. At 803 nm, $T_{2}^{2*}(450\,{\rm ps})$ becomes ten times longer than $T_{2}^{1*}(50\,{\rm ps})$ . A new feature has been discovered at the wavelength of 811 nm under the bias of $-0.3\,{\rm V}$ (807 nm under the bias of $-0.6\,{\rm V}$ ) that the spin coherence times ( $T_{2}^{1*}$ and $T_{2}^{2*}$ ) and the effective g^* factors ( $|g^{*}(E_{1})|$ and $|g^{*}(E_{2})|$ ) all display a sudden change, presumably due to the “resonant" spin exchange coupling between two spin opposite bands.

PACS: 72.25.Fe – Optical creation of spin polarized carriers / 72.25.Dc – Spin polarized transport in semiconductors / 78.47.-p – Spectroscopy of solid state dynamics

© EPLA, 2008

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.