Time-Dependent Spin-Density Functional Theory for strongly correlated systems

Luis Cort

Kieron Burke, Diego J. Carrascal, Jaime Ferrer +1 more

Volodymyr Turkowski, Talat S Rahman

We propose a nonadiabatic time-dependent spin-density functional theory (TDSDFT) approach for studying single-electron excited states and the ultrafast response of systems with strong electron correlations. The correlation part of the nonadiabatic exchange-correlation (XC) kernel is constructed by using exact results for the Hubbard model of strongly correlated electrons. We demonstrate that the corresponding nonadiabatic XC kernel reproduces the main features of the spectrum of the Hubbard dimer and the 2D, 3D and infinite-dimensional Hubbard models, some of which are impossible to obtain within the adiabatic approach. The formalism may be applied for ab initio examination of strongly correlated electron systems in- and out-of-equilibrium within the TDSDFT, extending it beyond the metallic and semiconductor structures with plasmons, excitons and other excitations.

Wei Li, Gao Xianlong, Corinna Kollath +1 more

Time-dependent density-functional theory (TDDFT) is a powerful tool in studying the nonequilibrium dynamics of inhomogeneous interacting many-body systems. Here we show that the simple adiabatic local-spin-density approximation for the time-dependent exchange-correlation potential is surprisingly accurate in describing collective density and spin dynamics in strongly correlated one-dimensional ultracold Fermi gases. Our conclusions are based on extensive comparisons between our TDDFT results and accurate results based on the adaptive time-dependent density-matrix renormalization-group method.

Swapan K. Ghosh

Zhixin Qian, Adi Constantinescu, Giovanni Vignale

It has been known for some time that the exchange-correlation potential in time-dependent density functional theory is an intrinsically nonlocal functional of the density as soon as one goes beyond the adiabatic approximation. In this paper we show that a much more severe nonlocality problem, with a completely different physical origin, plagues the exchange-correlation potentials in time-dependent spin density functional theory. We show how the use of the spin current density as the basic variable solves this problem, and we provide an explicit local expression for the exchange-correlation fields as functionals of the spin currents.