Quantum conductance fluctuations in semiconductor devices

Magneto-conductance fluctuations serve as the traditional method for investigating the dynamics of electrons as they flow through solid-state materials. Generated by electron wave interference, their spectral content is critically sensitive to the precise scattering configurations in the material. In this paper, we exploit this sensitivity to study the electron dynamics in the diffusive regime of semiconductors where the dynamics are determined by material-induced scattering. We show that the spectral content of the fluctuations measured on diffusive n+GaAs wires and quasi-ballistic AlGaAs/GaAs wires follow a fractal scaling behaviour similar to that previously observed in ballistic semiconductors. We present an interpretation based on chaotic dynamics generated by the material-induced disorder.