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HL: Fachverband Halbleiterphysik
HL 46: Transport properties II
HL 46.6: Vortrag
Donnerstag, 21. März 2024, 16:30–16:45, ER 325
Hall field-induced resistance oscillations in two-dimensional Lorentz gases — •Frederik Bartels1, Johannes Strobel1, Mihai Cerchez1, Klaus Pierz2, Hans W. Schumacher2, Dominique Mailly3, and Thomas Heinzel1 — 1Condensed Matter Physics Laboratory, Heinrich Heine University, Düsseldorf, Germany — 2Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany — 3CNRS, Université Paris-Saclay, C2N Marcoussis, 91460 Marcoussis, France
Two-dimensional electronic systems in non-equilibrium exhibit some exciting phenomena. One phenomenon are Hall field-induced resistance oscillations (HIROs), which can be recognized in the magnetoresistance of a highly mobile sample. Applying a direct current (x-direction) generates a tilt of the Landau levels due to the additional Hall field (y-direction). Tunneling to a higher Landau level is therefore possible, whereby the maximum probability depends on the shift in the y-direction. From theoretical considerations, a HIRO maximum arises due to backscattering, because this leads to the maximum shift (by 2Rc) in the y-direction for a single scattering event. We have investigated HIROs as a function of the obstacle density in two-dimensional Lorentz gases. A monotonous increase of the HIRO period with increasing density of the designed obstacles is observed. At large current densities, the HIROs deviate even qualitatively from the theoretical expectations. In addition, we determined the quantum scattering time τq and the backscattering time τπ using the HIROs. The quantum scattering times from the HIROs are significantly larger than the quantum scattering time that can be determined from the Shubnikov-de Haas oscillations in the equilibrium.
Keywords: Lorentz gas; Two-dimensional electron gas; HIRO; non-equilibrium phenomena; magnetoresistance