Enlarged magnetic focusing radius of photoinduced ballistic currents
  We exploit GaAs-based quantum point contacts as mesoscopic detectors to analyze the ballistic flow of photogenerated electrons in a two-dimensional electron gas at a perpendicular magnetic field. Whereas charge transport experiments always measure the classical cyclotron radius, we show that this changes dramatically when detecting the photoinduced non-equilibrium current in magnetic fields. The experimentally determined radius of the trajectories surprisingly exceeds the classical cyclotron value by far. Monte Carlo simulations suggest electron-electron scattering as the underlying reason. 
Markus Stallhofer, Christoph Kastl, Marcel Br\"andlein, Dieter Schuh,   Werner Wegscheider, J\"org. P. Kotthaus, Gerhard Abs...
cond-mat.mes-hall