Temperature-dependent magnetoconductance in quantum wires: Effect of phonon scattering

A rigorous numerical formalism is presented for the conductance in quasi-one-dimensional systems dominated by phonon and elastic scattering. The formalism is applied to study the effects of phonon scattering and the interface-roughness scattering at low temperatures (T) on the T-dependent electron conductance in a multilevel single quantum wires (SQWR’s) and tunnel-coupled double quantum wires (DQWR’s) under a perpendicular magnetic field B. The effect of phonon scattering is significant when the thermal energy $k_{B}T$ is comparable to the energy separation between the Fermi level and the nearest unoccupied sublevel in SQWR’s and to the tunneling gap energy in DQWR’s. While the magnetoconductance decreases with increasing T in general, it displays a strikingly opposite behavior in certain regimes of B and T in DQWR’s because of the field-induced separation of the initial and final scattering-state wave functions into the two separate quantum wires.