Conductance fluctuations and 1/<i>f</i>noise in Bi

Abstract

The 1/f resistance noise of Bi films has been measured as a function of temperature and magnetic field over the ranges 0.3--300 K and 0--8 T, respectively. As the temperature decreases below 70 K, the noise increases, and at 1 K it is larger than at room temperature. Below 20 K the noise magnitude is reduced by a factor of 2 in the presence of a perpendicular magnetic field of magnitude ${\mathrm{\ensuremath{\Phi}}}_{0}$/${\mathit{L}}_{\mathrm{\ensuremath{\varphi}}}^{2}$, where ${\mathrm{\ensuremath{\Phi}}}_{0}$ is the flux quantum, and ${\mathit{L}}_{\mathrm{\ensuremath{\varphi}}}$ is the phase-breaking length. These phenomena show that below about 70 K the noise is enhanced by the interference of the conduction electrons on the scale of ${\mathit{L}}_{\mathrm{\ensuremath{\varphi}}}$, as described by Feng, Lee, and Stone.