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Determination of the complex microwave photoconductance of a single quantum dot

H. Qin·F. Simmel·R. H. Blick·J. P. Kotthaus·W. Wegscheider·M. Bichler
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Abstract

A small quantum dot containing approximately 20 electrons is realized in a two-dimensional electron system of an AlGaAs/GaAs heterostructure. Conventional transport and microwave spectroscopy reveal the dot's electronic structure. By applying a coherently coupled two-source technique, we are able to determine the complex microwave induced tunnel current. The amplitude of this photoconductance resolves photon-assisted tunneling (PAT) in the non-linear regime through the ground state and an excited state as well. The out-of-phase component (susceptance) allows to study charge relaxation within the quantum dot on a time scale comparable to the microwave beat period.

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H. Qin, F. Simmel, R. H. Blick, J. P. Kotthaus, W. Wegscheider, M. Bichler. 2000-11-10. Determination of the complex microwave photoconductance of a single quantum dot. https://doi.org/10.1103/physrevb.63.035320

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