Mapping from current densities to vector potentials in time-dependent current density functional theory

Current Densities in Density Functional Theory

It is well known that any given density ρ(x) can be realized by a determinantal wave function for N particles. The question addressed here is whether any given density ρ(x) and current density j(x) can be simultaneously realized by a (finite kinetic energy) determinantal wave function. In case the velocity field v(x) = j(x)/ρ(x) is curlfree, we provide a solution for all N , and we provide an e...

Stochastic time-dependent current-density-functional theory.

A time-dependent current-density-functional theory for many-particle systems in interaction with arbitrary external baths is developed. We prove that, given the initial quantum state |Psi0> and the particle-bath interaction operator, two external vector potentials A(r,t) and A'(r,t) that produce the same ensemble-averaged current density, j(r,t), must necessarily coincide up to a gauge transfor...

Nonequilibrium Green Functions in Time-dependent Current-density-functional Theory∗

We give an overview of the underlying concepts of time-dependent current-densityfunctional theory (TDCDFT). We show how the basic equations of TDCDFT can be elegantly derived using the time contour method of nonequilibrium Green function theory. We further demonstrate how the formalism can be used to derive explicit equations for the exchange-correlation vector potentials and integral kernels f...

Relaxation in time-dependent current-density-functional theory.

We apply the time-dependent current-density-functional theory to the study of the relaxation of a closed many-electron system evolving from a nonequilibrium initial state. We show that the self-consistent unitary time evolution generated by the exchange-correlation vector potential irreversibly drives the system to equilibrium. We also show that the energy dissipated in the Kohn-Sham system, i....

Time - dependent current - density - functional theory for molecules