We discuss a calculation of the nonlinear current fluctuations in a model metallic resistor at low temperatures in a constant electric field, $E$. The model used here neglects electron-electron and electron-phonon scattering. For a very large range of frequencies, electron-localization effects lead to low-frequency corrections to Johnson noise of the form $\frac{E^2}{{\left|\omega \right|}^{\frac{\mathrm{}(4-d)\mathrm{}}{2}}}$. Here $\omega$ is the frequency and $d$ is the dimensionality of the system ($d=2, 3$). The relevance of our results to recent theoretical attempts to explain $\frac{1}{f}$ noise is discussed.

• Received 7 March 1985

DOI:https://doi.org/10.1103/PhysRevLett.54.2631