Nonequilibrium transport through the Hubbard dimer

Abstract: We apply a computationally efficient approach to study the time- and energy-resolved spectral properties of a two-site Hubbard model using the nonequilibrium Green's function formalism. By employing the iterative generalized Kadanoff-Baym ansatz ($i$GKBA) within a time-linear framework, we avoid the computational cost of solving the full two-time Kadanoff-Baym equations. Spectral information is extracted by coupling the system to multiple narrow-band leads, establishing a direct analogy to photoemission experiments. Our results reveal correlation-induced shifts and broadenings of spectral features, along with a suppression of transient current oscillations. This approach provides a promising avenue for analyzing correlated electron dynamics in open quantum systems.