Näytetään aineistoja, joilla on samankaltainen nimeke tai asiasanat.

• Many-particle theory for time-dependent quantum transport in nanostructures 

  Myöhänen, Petri (University of Jyväskylä, 2012)

  During the recent decades, molecular electronics has established its place as one of the promising fields in the nanoscience. The possibility to manufacture and control molecular junctions where single molecules are ...

• A many-body approach to transport in quantum systems : From the transient regime to the stationary state 

  Ridley, Michael; Talarico, N. Walter; Karlsson, Daniel; Lo Gullo, Nicola; Tuovinen, Riku (IOP Publishing, 2022)

  We review one of the most versatile theoretical approaches to the study of time-dependent correlated quantum transport in nano-systems: the non-equilibrium Green's function (NEGF) formalism. Within this formalism, one can ...

• Merging Features from Green's Functions and Time Dependent Density Functional Theory : A Route to the Description of Correlated Materials out of Equilibrium? 

  Hopjan, M.; Karlsson, Daniel; Ydman, S.; Verdozzi, C.; Almbladh, C.-O. (American Physical Society, 2016)

  We propose a description of nonequilibrium systems via a simple protocol that combines exchangecorrelation potentials from density functional theory with self-energies of many-body perturbation theory. The approach, aimed ...

• Cutting rules and positivity in finite temperature many-body theory 

  Hyrkäs, Markku; Karlsson, Daniel; van Leeuwen, Robert (IOP Publishing, 2022)

  For a given diagrammatic approximation in many-body perturbation theory it is not guaranteed that positive observables, such as the density or the spectral function, retain their positivity. For zero-temperature systems ...

• Diagrammatic Expansion for Positive Spectral Functions in the Steady-State Limit 

  Hyrkäs, Markku; Karlsson, Daniel; van Leeuwen, Robert (Wiley - VCH Verlag GmbH & Co. KGaA, 2019)

  Recently, a method was presented for constructing self‐energies within many‐body perturbation theory that is guaranteed to produce a positive spectral function for equilibrium systems, by representing the self‐energy as a ...