Scanning capacitance imaging of compressible and incompressible quantum Hall effect edge strips

Suddards, M.E. and Baumgartner, A. and Henini, M. and Mellor, C.J. (2012) Scanning capacitance imaging of compressible and incompressible quantum Hall effect edge strips. New Journal of Physics, 14 . 08315/1-08315/12. ISSN 1367-2630

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Abstract

We use dynamic scanning capacitance microscopy to image compressible and incompressible strips at the edge of a Hall bar in a two-dimensional electron gas (2DEG) in the quantum Hall effect (QHE) regime. This method gives access to the complex local conductance, Gts, between a sharp metallic tip scanned across the sample surface and ground, comprising the complex sample conductance. Near integer filling factors we observe a bright stripe along the sample edge in the imaginary part of Gts. The simultaneously recorded real part exhibits a sharp peak at the boundary between the sample interior and the stripe observed in the imaginary part. The features are periodic in the inverse magnetic field and consistent with compressible and incompressible strips forming at the sample edge. For currents larger than the critical current of the QHE break-down the stripes vanish sharply and a homogeneous signal is recovered, similar to zero magnetic field. Our experiments directly illustrate the formation and a variety of properties of the conceptually important QHE edge states at the physical edge of a 2DEG.

Item Type: Article
Additional Information: Some volumes prior to November 2012 may have been published under a Creative Commons Attribution Non-Commercial Share Alike License, please check individual journals for confirmation.
Schools/Departments: University of Nottingham UK Campus > Faculty of Science > School of Physics and Astronomy
Depositing User: Liu, Mr Zhenxing
Date Deposited: 01 Apr 2014 08:35
Last Modified: 17 Sep 2016 00:54
URI: http://eprints.nottingham.ac.uk/id/eprint/2340

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