Correlation and entanglement measures in trapped few-particle systems

Quantum correlations in few-particle systems are discussed in dependence on the shape of the external confining potential. The energy spectra, as well as the natural orbitals and their occupation numbers, are determined by using the optimized configuration interaction method. Considering the inter-particle interactions of the contact type, the comparison of various entanglement measures is given for the full range of interaction strength from strongly attractive to repulsive values. Entropic correlation measures are also discussed for the case of long-range Coulomb interactions between the particles.