Sudden quench in a model Hamiltonian with interactions: The time-dependent components of Wigner's correlation

Based on the correlated ground-state wave function of an exactly solvable interacting one-dimensional two-electron model Hamiltonian we address the switch-off of the external confining interaction in order to calculate the exact time-evolving wave function from a correlated initial state. The Hartree-Fock approximation for the initial state of the model system is considered as well. By taking the differences of kinetic and potential energy terms obtained with these treatments, the time-dependent components of Wigner's correlation energy are determined.