REDUCTION OF QUANTIZED CONDUCTANCE AT LOW-TEMPERATURES OBSERVED IN 2 TO 10 MU-M-LONG QUANTUM WIRES

We observe a small but definite decrease in quantized conductance at low temperatures in 2 to 10 mum-long single-mode quantum wires. The temperature dependence is stronger in the longer wires. The conductance of the 2mum-long wire is nearly constant below a critical temperature, at which the thermal length becomes longer than the wire length, while that of the 5 and 10 mum-long wires decreases fairly monotonically with decreasing temperature. We will discuss the effect of mutual Coulomb interaction that is responsible for the change in quantized conductance observed as a function of temperature and wire length.