Non-monotonic magnetoresistance of two-dimensional electron systems in the ballistic regime

Abstract

We report experimental observations of a novel magnetoresistance (MR) behavior of two-dimensional electron systems in perpendicular magnetic field in the ballistic regime, for k_BTτ/\hbar>1. The MR grows with field and exhibits a maximum at fields B>1/μ, where μis the electron mobility. As temperature increases the magnitude of the maximum grows and its position moves to higher fields. This effect is universal: it is observed in various Si- and GaAs- based two-dimensional electron systems. We compared our data with recent theory based on the Kohn anomaly modification in magnetic field, and found qualitative similarities and discrepancies.

4 pages 3 figures