Electronic double excitations in quantum wells: Solving the two-time Kadanoff-Baym equations
Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität Kiel Leibnizstrasse 15, 24098 Kiel, Germany, EU
Accepted: 22 May 2012
For a quantum many-body system, the direct population of states of double-excitation character is a clear indication that correlations importantly contribute to its nonequilibrium properties. We analyze such correlation-induced transitions by propagating the nonequilibrium Green's functions in real time within the second Born approximation. As crucial benchmarks, we compute the absorption spectrum of few electrons confined in quantum wells of different width. Our results include the full two-time solution of the Kadanoff-Baym equations as well as of their time-diagonal limit and are compared to Hartree-Fock and exact diagonalization data.
PACS: 73.21.-b – Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems / 71.15.Qe – Excited states: methodology / 05.30.-d – Quantum statistical mechanics
© EPLA, 2012