Universal conductance fluctuations in silicon inversion-layer nanostructures

We measure the conductance variations of submicrometer inversion-layer segments in silicon devices, systematically changing the length, width, inelastic diffusion length, gate voltage, magnetic field, and temperature. Results agree with the theory of universal conductance fluctuations, demonstrating that random quantum interference causes rms conductance changes ΔG=$e^2$/h in each phase-coherent subunit of each segment. The random quantum interference is extremely sensitive to change of a single scatterer.