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arXiv · 1611.08816

A complete laboratory for transport studies of electron-hole interactions in GaAs/AlGaAs systems

Ugo Siciliani de Cumis·Joanna Waldie·Andrew F. Croxall·Deepyanti Taneja·Justin Llandro·Ian Farrer·Harvey E. Beere·David A. Ritchie
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Abstract

We present GaAs/AlGaAs double quantum well devices that can operate as both electron-hole (e-h) and hole-hole (h-h) bilayers, with separating barriers as narrow as 5 nm or 7.5 nm. With such narrow barriers, in the h-h configuration we observe signs of magnetic-field-induced exciton condensation in the quantum Hall bilayer regime. In the same devices we can study the zero-magnetic-field e-h and h-h bilayer states using Coulomb drag. Very strong e-h Coulomb drag resistivity (up to 10% of the single layer resistivity) is observed at liquid helium temperatures, but no definite signs of exciton condensation are seen in this case. Self-consistent calculations of the electron and hole wavefunctions show this might be because the average interlayer separation is larger in the e-h case than the h-h case.

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Ugo Siciliani de Cumis, Joanna Waldie, Andrew F. Croxall, Deepyanti Taneja, Justin Llandro, Ian Farrer, Harvey E. Beere, David A. Ritchie. 2016-11-27. A complete laboratory for transport studies of electron-hole interactions in GaAs/AlGaAs systems. https://doi.org/10.1063/1.4976505

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