Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport

Recently, it has been possible to design independently contacted electron-hole bilayers (EHBLs) with carrier densities <5×1010 cm2 in each layer and a separation of 10–20 nm in a GaAs/AlGaAs system. In these EHBLs, the interlayer interaction can be stronger than the intralayer interactions. Theor...

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Main Authors: K. Das Gupta, A. F. Croxall, J. Waldie, C. A. Nicoll, H. E. Beere, I. Farrer, D. A. Ritchie, M. Pepper
Format: Article
Language:English
Published: Wiley 2011-01-01
Series:Advances in Condensed Matter Physics
Online Access:http://dx.doi.org/10.1155/2011/727958
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author K. Das Gupta
A. F. Croxall
J. Waldie
C. A. Nicoll
H. E. Beere
I. Farrer
D. A. Ritchie
M. Pepper
author_facet K. Das Gupta
A. F. Croxall
J. Waldie
C. A. Nicoll
H. E. Beere
I. Farrer
D. A. Ritchie
M. Pepper
author_sort K. Das Gupta
collection DOAJ
description Recently, it has been possible to design independently contacted electron-hole bilayers (EHBLs) with carrier densities <5×1010 cm2 in each layer and a separation of 10–20 nm in a GaAs/AlGaAs system. In these EHBLs, the interlayer interaction can be stronger than the intralayer interactions. Theoretical works have indicated the possibility of a very rich phase diagram in EHBLs consisting of excitonic superfluid phases, charge density waves, and Wigner crystals. Experiments have revealed that the Coulomb drag on the hole layer shows strong nonmonotonic deviations from a ∼𝑇2 behaviour expected for Fermi-liquids at low temperatures. Simultaneously, an unexpected insulating behaviour in the single-layer resistances (at a highly “metallic” regime with 𝑘𝐹𝑙>500) also appears in both layers despite electron mobilities of above ∼106cm2V−1s−1 and hole mobilities over ∼105cm2V−1s−1. Experimental data also indicates that the point of equal densities (𝑛=𝑝) is not special.
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institution Kabale University
issn 1687-8108
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publishDate 2011-01-01
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series Advances in Condensed Matter Physics
spelling doaj-art-6603b4d04f764c29bb3ced029880f5e82025-02-03T06:11:27ZengWileyAdvances in Condensed Matter Physics1687-81081687-81242011-01-01201110.1155/2011/727958727958Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature TransportK. Das Gupta0A. F. Croxall1J. Waldie2C. A. Nicoll3H. E. Beere4I. Farrer5D. A. Ritchie6M. Pepper7Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKCavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UKRecently, it has been possible to design independently contacted electron-hole bilayers (EHBLs) with carrier densities <5×1010 cm2 in each layer and a separation of 10–20 nm in a GaAs/AlGaAs system. In these EHBLs, the interlayer interaction can be stronger than the intralayer interactions. Theoretical works have indicated the possibility of a very rich phase diagram in EHBLs consisting of excitonic superfluid phases, charge density waves, and Wigner crystals. Experiments have revealed that the Coulomb drag on the hole layer shows strong nonmonotonic deviations from a ∼𝑇2 behaviour expected for Fermi-liquids at low temperatures. Simultaneously, an unexpected insulating behaviour in the single-layer resistances (at a highly “metallic” regime with 𝑘𝐹𝑙>500) also appears in both layers despite electron mobilities of above ∼106cm2V−1s−1 and hole mobilities over ∼105cm2V−1s−1. Experimental data also indicates that the point of equal densities (𝑛=𝑝) is not special.http://dx.doi.org/10.1155/2011/727958
spellingShingle K. Das Gupta
A. F. Croxall
J. Waldie
C. A. Nicoll
H. E. Beere
I. Farrer
D. A. Ritchie
M. Pepper
Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
Advances in Condensed Matter Physics
title Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
title_full Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
title_fullStr Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
title_full_unstemmed Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
title_short Experimental Progress towards Probing the Ground State of an Electron-Hole Bilayer by Low-Temperature Transport
title_sort experimental progress towards probing the ground state of an electron hole bilayer by low temperature transport
url http://dx.doi.org/10.1155/2011/727958
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