The role of many-particle excitations in Coulomb blockaded transport

Abstract

We discuss the role of electron–electron and electron–phonon correlations in current flow inthe Coulomb blockade regime, focusing specifically on non-trivial signatures arisingfrom the breakdown of mean-field theory. By solving transport equations directlyin Fock space, we show that electron–electron interactions manifest as gateableexcitations experimentally observed in the current–voltage characteristic. While theseexcitations might merge into an incoherent sum that allows occasional simplifications, aclear separation of excitations into slow ‘traps’ and fast ‘channels’ can lead tofurther novelties such as negative differential resistance, hysteresis and randomtelegraph signals. Analogous novelties for electron–phonon correlation include thebreakdown of commonly anticipated Stokes–anti-Stokes intensities, and an anomalousdecrease in phonon population upon heating due to reabsorption of emitted phonons.