Kadanoff-Baym ansatz

The self-energy of the right electrode is similarly defined. How to define the lesser (greater) self-energy, which represents the scatter-in (out) function ofelectrons provided by electrodes, is the central issue. Practical applications of the NEGF will be possible if the (generalized) Kadanoff-Baym ansatz is applicable [67-69, 77]. In the E-M-E system under constant bias Vb, electrodes are the electron reservoirs by means of the Landauer picture thus they can be approximated as a non-interacting quasi-equilibrium system,... 

Lipavsky, P., Spicka, V. and Velicky, B. (1986) Generalized Kadanoff-Baym Ansatz for Deriving Quantum Transport-Equations. Phys. Rev. B, 34, 6933-6942. 

By using the nonequilibrium Green function method with gradient expression as well as the generalized Kadanoff-Baym Ansatz [24], we construct the KSBEs as follows ... 

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