The Johnson-Nyquist noise in narrow wires having a transverse size smaller than the screening length is shown to be white up to the frequency D/L2 and to decay at higher frequencies as ω−1/2. In two-dimensional films having a thickness smaller than the screening length, the Johnson-Nyquist noise is predicted to be frequency independent up to the frequency σ2D/L and to have a {\it universal} 1/ω spectrum at higher frequencies. These results are contrasted with the conventional noise spectra in neutral and three-dimensional charged liquids.
@article{arxiv.cond-mat/0002153,
title = {Johnson-Nyquist noise in films and narrow wires},
author = {Misha Turlakov},
journal= {arXiv preprint arXiv:cond-mat/0002153},
year = {2009}
}