Conductance fluctuations in mesoscopic conductors at low temperatures

This paper is a tutorial introduction to the subject of conductance fluctuations observed in mesoscopic conductors at low temperatures, and the universal conductance fluctuation (UCF) theory proposed to explain them. The discovery of the fluctuations less than a decade ago has been followed by an intensive flurry of research activity, published almost entirely in the journals of solid-state physics. This paper surveys the subject from the viewpoint of a practising electron device engineer, with bias in favor of intuitive appeal rather than rigor, and should be helpful in understanding the primary literature on the subject. The nature of fluctuations and mesoscopic conduction are briefly introduced. Both theoretical and experimental results from the sizable literature on the subject are summarized here, emphasizing the characteristics of the fluctuations, the conditions under which they are observed, the mechanism of fluctuations, and the range of applicability of the UCF theory