Magnetoconductance of Si MOSFET Quantum Wires: Weak Localization and Magnetic Depopulation of 1D Subbands

The magneto-electric transport in narrow (≈70 nm), parallel multiple quantum wires in Si MOSFET’s has been studied at different gate voltages and in magnetic fields up to 20 T. For high gate voltages the low field magnetoconductance due to weak localization can be described well by existing theory, that we have utilized to extract the channel width and the inelastic diffusion length. From quantum oscillations in the conductance as a function of magnetic field we find that the plot of subband index n vs inverse magnetic field is nonlinear due to magnetic depopulation of ID subbands.