Electric field effects and screening in mesoscopic bismuth wires

Large time-independent conduction fluctuations were observed as a function of transverse electric field in thin (25 nm) and narrow (60 nm) bismuth wires. The conduction of leads far away from a gate capacitor was influenced by changes in the gate voltage. The effects are interpreted as being due to a variation in the Fermi wavelength caused by gate-induced changes in the charge concentration of the leads rather than an electrostatic Aharonov-Bohm-type interference. The screening of charge is strongly reduced in narrow wires