Ultrafast dynamics of coherences in a quantum Hall system

Using three-pulse four-wave-mixing optical spectroscopy, we study the ultrafast dynamics of the quantum Hall system. We observe striking differences as compared to an undoped system, where the 2D electron gas is absent. In particular, we observe a large off-resonant signal with strong oscillations....

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Bibliographic Details
Published inPhysical review letters Vol. 97; no. 5; p. 057401
Main Authors Dani, K M, Tignon, J, Breit, M, Chemla, D S, Kavousanaki, E G, Perakis, I E
Format Journal Article
LanguageEnglish
Published United States 04.08.2006
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Summary:Using three-pulse four-wave-mixing optical spectroscopy, we study the ultrafast dynamics of the quantum Hall system. We observe striking differences as compared to an undoped system, where the 2D electron gas is absent. In particular, we observe a large off-resonant signal with strong oscillations. Using a microscopic theory, we show that these are due to many-particle coherences created by interactions between photoexcited carriers and collective excitations of the 2D electron gas. We extract quantitative information about the dephasing and interference of these coherences.
ISSN:0031-9007
DOI:10.1103/physrevlett.97.057401