The Hall effect and localized transport

R Robert Carroll (London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,) G Gregory Auton (London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,) S Stuart N. Holmes (Department of Electronic and Electrical Engineering, University College London 2 , Torrington Place, London WC1E 7JE,) C Chong Chen (Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University) D David A. Ritchie M Michael Pepper (London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,)

Abstract

Historically, in measurements of electron transport in disordered two-dimensional systems, an Arrhenius Hall carrier density has never been observed alongside an Arrhenius conductivity, when the Fermi level is below a mobility edge. This has long been an issue with respect to claiming observation of transport via activation to a mobility edge. In this work, an Arrhenius conductivity and Arrhenius Hall carrier density have been observed alongside one another in such a system. Measurements were made of a two-dimensional electron gas hosted in a gated GaAs/Al0.33Ga0.67As heterostructure. Furthermore, in the regime of Arrhenius conductivity and Arrhenius carrier density, the mobility is shown to be independent of the position of the Fermi level below the mobility edge. A transition between carrier density and mobility dominating the resistivity temperature dependence has been observed, as the Fermi level is varied.

Article Details

Volume / Issue Vol. 127, Issue 22
Published December 01, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (6)

R

Robert Carroll

London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,

G

Gregory Auton

London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,

S

Stuart N. Holmes

Department of Electronic and Electrical Engineering, University College London 2 , Torrington Place, London WC1E 7JE,

C

Chong Chen

Department of Thoracic Oncology, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University

D

David A. Ritchie

M

Michael Pepper

London Centre for Nanotechnology, University College London 1 , 17-19 Gordon Street, London WC1H 0AH,