Transition from excitonic tunneling to free carrier tunneling in GaAs/AlGaAs double quantum wells

Shulong Lu, Takafumi Ushiyama, Taisuke Fujita, Koji Kusunoki, Atsushi Tackeuchi, Shunichi Muto

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    Abstract

    Nonresonant carrier tunneling has been studied as a function of temperature in GaAs/AlGaAs double quantum wells (DQWs). Time-resolved pump and probe reflectance measurements allow the direct observation of tunneling at any temperature between 15 K and room temperature. We found that for two DQWs with different barrier thicknesses, the tunneling time abruptly decreases above a critical temperature while it remains almost constant below the critical temperature. This critical temperature is shown to correspond to the exciton binding energy. Rate equation analysis explains this behavior as the thermalization of excitons into free electrons that have a faster tunneling time than excitons.

    Original languageEnglish
    Pages (from-to)3305-3308
    Number of pages4
    JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
    Volume46
    Issue number6 A
    DOIs
    Publication statusPublished - 2007 Jun 6

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    Keywords

    • Double quantum wells
    • Excitons
    • Pump-probe
    • Tunneling

    ASJC Scopus subject areas

    • Physics and Astronomy (miscellaneous)

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