Electron spin-relaxation dynamics in GaAs/AlGaAs quantum wells and InGaAs/InP quantum wells

Atsushi Tackeuchi, Takamasa Kuroda, Shunichi Muto, Yuji Nishikawa, Osamu Wada

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    We have investigated the spin-relaxation process of electrons at room temperature in undoped GaAs/AlGaAs multiple-quantum wells (MQWs) and InGaAs/InP MQWs. The spin-relaxation times are measured for different well thicknesses using time-resolved spin-dependent pump and probe absorption measurement. The spin-relaxation time, τs, for GaAs MQWs was found to depend on the electron confinement energy, E1e, according to τs ∝ E1e -2.2, demonstrating that the main spin-relaxation mechanism at room temperature is the D'yakonov-Perel' process. The measured spin-relaxation times of InGaAs MQWs whose band-gap is about half that of GaAs MQWs arc about 5 ps and vary depending on the quantum confinement energy, E1e, according to τs ∝ E1e -1.0. The spin-relaxation time by Elliott-Yafet process, which becomes stronger for narrower band-gap materials, is calculated for quantum wells and shown to vary according to τs ∝ E1e -1. The spin-relaxation mechanism and possible applications using this fast spin-relaxation process are discussed.

    Original languageEnglish
    Pages (from-to)4680-4687
    Number of pages8
    JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
    Issue number8 B
    Publication statusPublished - 1999 Aug 15



    • D'yakonov-Perel'
    • Electron
    • Elliott-Yafet
    • InGaAs
    • MOW
    • Spin-relaxation

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

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