Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 32: Transport Properties I (mainly Spin Physics and Magnetic Fields)
HL 32.2: Vortrag
Dienstag, 27. März 2012, 10:15–10:30, EW 203
Interaction-Induced Huge Magnetoresistance in a High Mobility Two-Dimensional Electron Gas — •Lina Bockhorn1, Aida Hodai1, Igor V. Gornyi2, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, 30167 Hannover — 2Institut für Nanotechnologie, Forschungszentrum Karlsruhe, 76021 Karlsruhe
We study magneto transport in a high mobility two-dimensional electron gas (2DEG). Hall geometries are created by photolithography on a GaAs/GaAlAs quantum well containing a 2DEG. The 2DEG has an electron density of ne=3.1·1011cm−2 and a mobility of µe=11.9·106cm2/Vs at a temperature of 1.5 K. We observe a strong negative magnetoresistance at zero magnetic field. In lowering the electron density the magnetoresistance gets more pronounced and reaches values of more than 300 % [1]. We demonstrate that the negative magnetoresistance consists of a small peak induced by a combination of at least two types of disorder [2] and a huge magnetoresistance explained by the interaction correction to the conductivity for mixed disorder [3,4]. The huge magnetoresistance vanishes for increasing the temperature from 100 mK to 800 mK while the small peak remains unchanged.
[1] L. Bockhorn et al., Phys. Rev. B 83, 113301 (2011)
[2] A. D. Mirlin et al., Phys. Rev. Lett. 87, 126805 (2001).
[3] I. V. Gornyi and A. D. Mirlin, Phys. Rev. Lett. 90, 076801 (2003)
[4] I. V. Gornyi and A. D. Mirlin, Phys. Rev. B 69, 045313 (2004)