Speaker
Description
Describing strongly interacting electrons is one of the crucial challenges of modern quantum
physics. A comprehensive solution to this electron correlation problem would simultaneously
exploit both the pairwise interaction and its spatial decay. By taking a quantum information
perspective, we explain how this structure of realistic Hamiltonians gives rise to two
conceptually different notions of correlation and entanglement. The first one describes
correlations between orbitals while the second one refers more to the particle picture. We
illustrate those two concepts of orbital and particle correlation and present measures thereof.
Our results for different molecular systems reveal that the total correlation between molecular
orbitals is mainly classical, raising questions about the general significance of entanglement
in chemical bonding. Finally, we also speculate on a promising relation between orbital and
particle correlation and explain why this may replace the obscure but widely used concept of
static and dynamic correlation.