Nonequilibrium variational-cluster approach to real-time dynamics in the Fermi-Hubbard model

Progress in Non-equilibrium Green's Functions

Hofmann, Felix^1 ; Eckstein, Martin^2 ; Potthoff, Michael^1

I. Institut für Theoretische Physik, Universität Hamburg, Jungiusstraße 9, Hamburg

20355, Germany^1

Max Planck Research Department for Structural Dynamics, University of Hamburg, CFEL, Notkestraße 85, Hamburg

22607, Germany^2

关键词: Cluster approach;    Hopping parameters;    Numerical implementation;    Numerically tractable;    Real-time dynamics;    Reference systems;    Time derivative;    Variational parameters;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/696/1/012002/pdf
DOI  :  10.1088/1742-6596/696/1/012002

来源: IOP

【 摘 要 】

The nonequilibrium variational-cluster approach is applied to study the real-time dynamics of the double occupancy in the one-dimensional Fermi-Hubbard model after different fast changes of hopping parameters. A simple reference system, consisting of isolated Hubbard dimers, is used to discuss different aspects of the numerical implementation of the approach in the general framework of nonequilibrium self-energy functional theory. Opposed to a direct solution of the Euler equation, its time derivative is found to serve as numerically tractable and stable conditional equation to fix the time-dependent variational parameters.