Full Current Statistics of Incoherent "Cold Electrons"

Abstract

We evaluate the full current statistics (FCS) in the low dimensional (1D and 2D) diffusive conductors in the incoherent regime, $eV\gg E_{\rm Th}=D/L^2$, $E_{\rm Th}$ being the Thouless energy. It is shown that Coulomb interaction substantially enhances the probability of big current fluctuations for short conductors with $E_{\rm Th}\gg1/\tau_E$, $\tau_E$ being the energy relaxation time, leading to the exponential tails in the current distribution. The current fluctuations are most strong for low temperatures, provided $E_{\rm Th}\sim [(eV)^2/D\nu_1^2\bigr]^{1/3}$ for 1D and $E_{\rm Th}\sim (eV/g)\ln g$ for 2D, where $g$ is a dimensionless conductance and $\nu_1$ is a 1D density of states. The FCS in the "hot electron" regime is also discussed.