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Magnetization measurements of high-mobility two-dimensional electron gases

Magnetization measurements of high-mobility two-dimensional electron gases
Magnetization measurements of high-mobility two-dimensional electron gases
De Haas-van Alphen (dHvA) oscillations are observed for Landau levels (LLs) with filling factors between 4 and 52, at temperatures in the range 50 mK to 1 K, in experiments on high mobility GaAs/(Al, Ga)As heterojunctions. The oscillations become sawtooth-shaped at low filling factors, and theoretical fits to the data, assuming the two-dimensional electron gas to be a non-interacting Fermi system, show the shape of LLs to be close to a ?-function. The small residual width (~0.4 meV or less) fits equally well to either a Gausian or a Lorentzian density of states model. In almost all cases, a constant background density of states has to be included to obtain a satisfactory fit. weak odd-filling-factor dHvA peaks are detected at high fields, from which a g-factor enhancement of 15 can be inferred. Comparison of the scattering time derived from the fits before and after illumination, with the momentum relaxation time derived from transport, reveals a counterintuitive behavior in the bulk-modulation-doped sample.
1550-235X
155329
Zhu, M.
3f4cc18c-a721-4422-93c0-5cf03bd1f9da
Usher, A.
c35eff09-3353-4b8c-a735-8272a3ced1f8
Matthews, A. J.
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Potts, A.
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Elliott, M.
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Herrenden-Harker, W. G.
e9030a74-e078-4d68-8efc-99d753fd65e8
Ritchie, D. A.
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Simmons, M. Y.
6a05d50b-57f0-4d71-a4ae-5a38cede98f0
Zhu, M.
3f4cc18c-a721-4422-93c0-5cf03bd1f9da
Usher, A.
c35eff09-3353-4b8c-a735-8272a3ced1f8
Matthews, A. J.
181809e8-3bc1-4004-9c24-ff6e32b7c984
Potts, A.
60d57f4c-abcf-4b6b-8247-28711e6fd4d4
Elliott, M.
72144b37-250f-4bf8-8454-0c17e1318bfa
Herrenden-Harker, W. G.
e9030a74-e078-4d68-8efc-99d753fd65e8
Ritchie, D. A.
efa64786-3cb8-47f4-98d5-e8cce27bb1e7
Simmons, M. Y.
6a05d50b-57f0-4d71-a4ae-5a38cede98f0

Zhu, M., Usher, A., Matthews, A. J., Potts, A., Elliott, M., Herrenden-Harker, W. G., Ritchie, D. A. and Simmons, M. Y. (2003) Magnetization measurements of high-mobility two-dimensional electron gases. Physical Review B, 67, 155329.

Record type: Article

Abstract

De Haas-van Alphen (dHvA) oscillations are observed for Landau levels (LLs) with filling factors between 4 and 52, at temperatures in the range 50 mK to 1 K, in experiments on high mobility GaAs/(Al, Ga)As heterojunctions. The oscillations become sawtooth-shaped at low filling factors, and theoretical fits to the data, assuming the two-dimensional electron gas to be a non-interacting Fermi system, show the shape of LLs to be close to a ?-function. The small residual width (~0.4 meV or less) fits equally well to either a Gausian or a Lorentzian density of states model. In almost all cases, a constant background density of states has to be included to obtain a satisfactory fit. weak odd-filling-factor dHvA peaks are detected at high fields, from which a g-factor enhancement of 15 can be inferred. Comparison of the scattering time derived from the fits before and after illumination, with the momentum relaxation time derived from transport, reveals a counterintuitive behavior in the bulk-modulation-doped sample.

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Published date: April 2003
Organisations: Nanoelectronics and Nanotechnology

Identifiers

Local EPrints ID: 262117
URI: http://eprints.soton.ac.uk/id/eprint/262117
ISSN: 1550-235X
PURE UUID: 2d79b321-062b-41b2-9dec-8eec8774744b

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Date deposited: 23 Mar 2006
Last modified: 02 Dec 2019 21:07

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