Full counting-statistics in a single-electron transistor in the presence of nonequilibrium quantum fluctuations of charge

Using the Schwinger-Keldysh approach and the drone (Majorana) fermion representation, we evaluate current distribution in a single-electron transistor in a regime where a total tunnel resistance is small. Nonequilibrium quantum fluctuations of charge induce a lifetime broadening of charge-state level, as well as renormalization of system parameters. We find that the lifetime broadening effect may suppress the probability of relatively large current.Comment: 4 pages, 1 figur