EFFECTS OF A DC-BIAS VOLTAGE ON THE MAGNETORESISTANCE OF ELECTRON BILLIARDS

The effect of a de-bias voltage on the magnetoresistance of different electron billiards is studied. It is found that with increasing de-bia s maxima of the magnetoresistance disappear and turn into minima and v ice versa in some billiard geometries. A substantially increased noise level is also observed. The observed effects are too large to be expl ained by changes of simple ballistic trajectories due to the induced s hift in the electron velocity. As possible mechanisms that could accou nt for the observed effects, we discuss the voltage induced changes of the billiard geometry and the suppression of unstable trajectories du e to electron-electron scattering. The effect of small angle scatterin g is studied using classical simulations of electron transport.