1 research outputs found
Time-dependent density-functional and reduced density-matrix methods for few electrons: Exact versus adiabatic approximations
To address the impact of electron correlations in the linear and non-linear
response regimes of interacting many-electron systems exposed to time-dependent
external fields, we study one-dimensional (1D) systems where the interacting
problem is solved exactly by exploiting the mapping of the 1D -electron
problem onto an -dimensional single electron problem. We analyze the
performance of the recently derived 1D local density approximation as well as
the exact-exchange orbital functional for those systems. We show that the
interaction with an external resonant laser field shows Rabi oscillations which
are detuned due to the lack of memory in adiabatic approximations. To
investigate situations where static correlations play a role, we consider the
time-evolution of the natural occupation numbers associated to the reduced
one-body density matrix. Those studies shed light on the non-locality and
time-dependence of the exchange and correlation functionals in time-dependent
density and density-matrix functional theories.Comment: 19 pages, 13 figures, version as published apart from layou