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

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

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

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.

Original languageEnglish
Article number072105
JournalApplied Physics Letters
Volume110
Issue number7
DOIs
Publication statusPublished - 2017 Feb 13
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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