BALLISTIC CONDUCTANCE FLUCTUATIONS IN SHAPE SPACE

Ballistic conductance fluctuations were measured in a GaAs quantum dot as a function of shape distortion and magnetic field. Shape distortion provides a novel source of conductance fluctuations and creates an effective “ensemble of dots,” allowing statistics to be studied at fixed field. Continuous changes in fluctuation statistics due to breaking of time-reversal symmetry are seen about zero magnetic field. Throughout, conductance fluctuation distributions appear Gaussian. The power spectrum of shape fluctuations appears exponential over three decades.