Temperature dependence of phonon-induced current noise in micrometer-long metallic carbon nanotubes

We theoretically investigate the temperature dependence of phonon-induced current noise in micrometer-long metallic single-walled carbon nanotubes using large-scale time-dependent quantum transport simulations. We find that both the average current and its variance exhibit power-law dependencies on temperature in the high-temperature diffusive regime: (J K )α 1/T and (ΔJ K 2 )α 1/T 2 , respectively. The observed 1/T 2 behavior of the current variance stands in stark contrast to the equilibrium Johnson-Nyquist noise, which increases linearly with temperature. Furthermore, we show that the current variance follows a universal scaling law as a function of the normalized channel length L/L 0 , where L 0 denotes the phonon-limited mean free path. This behavior is quantitatively explained by a Gamma-distributed probability density function for the current, combined with a phenomenological model for electronic transport incorporating dephasing effects due to electron-phonon scattering.