Nonequilibrium blockade

In the case of a single site junction with two (spin-up and spin-down) states and Coulomb interaction between these states (Anderson impurity model), the linear conductance properties have been successfully studied by means of the EOM approach in the cases related to Coulomb blockade [203, 204] and the Kondo effect [205]. Later the same method was applied to some two-site models [206-209], Multi-level systems were started to be considered only recently [210,211], Besides, there are some difficulties in building the lesser GF in the nonequilibrium case (at finite bias voltages) by means of the EOM method [212-214],... 

The other important point is that the distribution function fn a) in the charge state n) is not assumed to be equilibrium, as previously (this condition is not specific to quantum dots with discrete energy levels, the distribution function in metallic islands can also be nonequilibrium. However, in the parameter range, typical for classical Coulomb blockade, the tunneling time is much smaller than the energy relaxation time, and quasiparticle nonequilibrium effects are usually neglected). 

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