Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 42: Transport

HL 42.1: Vortrag

Donnerstag, 15. März 2018, 15:00–15:15, EW 015

Linear magnetoresistance in ultra-high mobility GaAs quantum wells with a parabolic dispersion — •Thomas Khouri¹, Uli Zeitler¹, Christian Reichl², Werner Wegscheider², Nigel Hussey¹, Steffen Wiedmann¹, and Jan Kees Maan¹ — ¹High Field Magnet Laboratory (HFML-EMFL), Radboud University, Nijmegen 6525 ED, NL — ²Laboratory for Solid State Physics, ETH Zürich, 8093 Zürich, Switzerland

The observation of a linear magnetoresistance is often invoked as evidence for exotic quasiparticles in new materials such as topological semi-metals, though its origin remains controversial. Here we show that a strong non-saturating LMR is observable in GaAs quantum wells with a parabolic dispersion and ultra-high mobility (μ*25*106 cm2 V-1s-1). This LMR persists over a large magnetic field range up to 33 T and a wide temperature range between 0.3 K and 60 K. The simplicity of our system in combination with an almost defect-free environment allows us to exclude most exotic explanations that are known to give rise to a LMR. Instead our analysis suggests that small density fluctuations are the primary origin of the phenomenon. Interestingly, both the LMR and the quantum oscillations at low temperatures obey the empirical resistance rule with an α that remains unchanged over the entire temperature range. Only at low temperatures, small deviations from this resistance rule are observed beyond ν=1.