NONUNIVERSAL CONDUCTANCE QUANTIZATION IN HIGH-QUALITY QUANTUM WIRES

We present a theoretical analysis of recent experimental results of Ya coby et al. on transport properties of high-quality quantum wires. We suggest an explanation of observed deviations of the conductance from the universal value 2e(2)/h per channel in the wire. We argue that at low temperatures and biases the deviation can be a consequence of anom alously enhanced backscattering of electrons entering the two-dimensio nal electron gas from the wire and is not connected to intrinsic prope rties of a one-dimensional electron gas.