Low-frequency fluctuations in solids: 1f noise

An astonishing variety of systems show properties that fluctuate with approximately 1f-shaped spectral densities. In this review we deal with selected topics regarding 1f fluctuations (or noise) in the resistance of simple condensed matter systems, especially metals. We find that considerable experimental and conceptual progress has been made, but specific physical processes mostly remain to be identified. © 1981 American Physical Society.