CONDUCTANCE QUANTIZATION IN BISMUTH NANOWIRES AT 4 K

Conductance experiments on Bi nanowires at 4 K, obtained with a scanni ng tunneling microscope, are presented. The conductance of these Bi na nocontacts, formed between two Bi electrodes, exhibits plateaus at qua ntized values of G(0) = 2e(2)/h, remaining basically constant during e lectrode separations of about 50 nm. This is the first rime that such plateaus have been observed in semimetals. This histogram of conductan ce values, constructed with thousands of consecutive contact breakage conductance experiments. exhibits clear peaks at G(0) and 2G(0).