Temperature dependent third cumulant of tunneling noise

Original · EN

Poisson statistics predicts that the shot noise in a tunnel junction has a temperature independent third cumulant e², determined solely by the mean current I. Experimental data, however, show a puzzling temperature dependence. We demonstrate theoretically that the third cumulant becomes strongly temperature dependent and may even change sign as a result of feedback from the electromagnetic environment. In the limit of a noninvasive (zero-impedance) measurement circuit in thermal equilibrium with the junction, we find that the third cumulant crosses over from e²/I at low temperatures to -e²/I at high temperatures.