Conductance quantization and zero bias peak in a gated quantum wire

Conductance measurements are reported for an 0.4 μm wide GaAs/AlGaAs quantum wire with 7 cross-channel gates. The device exhibited integral conductance steps, magnetoconductance plateaus in agreement with the multiprobe formula and a conductance feature at 0.65(2e2/h). Differential conductance measurements down to 50 mK revealed a zero bias conductance peak that vanished with an in-plane field of 1 T. The width of this peak was comparable to that reported in high mobility quantum point contacts (Phys. Rev. Lett. 88 (2002) 226805). At low conductances this device also exhibited single electron charging characteristic of a multiple quantum dot.