The noise produced by thermodynamic fluctuations (e.g., in carrier number) is shown to diverge for ideal contact (spreading) resistors. For diffusion-controlled fluctuations the frequency spectrum is shown to be proportional to ${\omega }^{-1\mathrm{}}$ (i.e., $\frac{1}{f}$) for high frequencies. This behavior is shown to be approached by resistors whose surfaces have sharp corners. The relation to observed noise is briefly discussed.

• Received 2 June 1975

DOI:https://doi.org/10.1103/PhysRevLett.35.689