Magnetization Measurements of High-Mobility Two-Dimensional Electron Gases

Elliott, Martin ORCID: https://orcid.org/0000-0002-9254-9898, Richie, D. A, Usher, A. and Zhu, M. 2003. Magnetization Measurements of High-Mobility Two-Dimensional Electron Gases. Physical Review B 67 (15) , 155329. 10.1103/PhysRevB.67.155329

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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 δ function. The small residual width (∼0.4 meV or less) fits equally well to either a Gaussian 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.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Physics and Astronomy
Subjects:	Q Science > QC Physics
Publisher:	American Physical Society
ISSN:	1098-0121
Last Modified:	06 May 2023 17:14
URI:	https://orca.cardiff.ac.uk/id/eprint/1623

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