Anomalous sensitivity of high-mobility interacting 2D electron gas to a weak magnetic field

Mikhail Raikh

University of Utah, USA

Thermodynamic and transport characteristics of a clean two-dimensional interacting electron gas are shown to be sensitive to the weak perpendicular magnetic field even at temperatures much higher than the cyclotron energy, when the quantum oscillations are completely washed out. The origin of the sensitivity is traced to the field-induced smearing of the Kohn anomaly; this smearing is the result of curving of the semiclassical electron trajectories in magnetic field.
In the presence of a weak disorder this sensitivity gives rise to the new observable effects, namely
1. oscillating correction to the tunnel density of states
2. interaction-induced oscillations of the AC magnetoconductivity
3. strong DC magnetoresistance in the crossover domain between weak localization and Shubnikov-de Haas oscillations