Spatial and temporal spectra of noise driven stripe patterns

Spatial and temporal noise power spectra of stripe patterns are investigated, using as a model a Swift-Hohenberg equation with a stochastic term. In particular, the analytical and numerical investigations show: 1) the temporal noise spectra are of 1/f^alpha form, where alpha=1+(3-D)/4 with D the spatial dimension of the system; 2) that the stochastic fluctuations of the stripe position are sub-diffusive.Comment: Submitted to PR

Power and temperature dependence of low frequency noise in AlGaN/GaN transmission line model structures

The low-frequency noise in AlGaN/GaN transmission line model structures has been investigated for a wide range of ambient temperatures and dissipated powers. A deviation of low-frequency noise from a 1/f dependence has been observed upon increasing the applied voltage. The effect correlates with the nonlinearity of current-voltage characteristics (CVC). The concept of nonequilibrium 1/f noise has been introduced to explain 1/f noise enhancement. A qualitative model connecting non-equilibrium noise with nonlinearity of the CVC via a common origin-nonuniform overheating of the structures-has been suggested. Furthermore, deviations of equilibrium noise from the 1/f law at low temperatures have been observed and studied. (C) 2004 American Institute of Physics