Thomas Papenbrock, University of Tennessee

Entanglement entropies are a measure of the complexity of quantum states. In nuclear systems one often starts from a mean-field (product) state and this makes it useful to determine the entanglement entropy between the single-particle states of the hole space and its complement in nuclear systems. Analytical results based on the coupled-cluster method show that entanglement entropies are proportional to the particle number fluctuation and the depletion number of the hole space for sufficiently weak interactions. General arguments also suggest that the entanglement entropy in nuclear systems fulfills a volume instead of an area law, when based on the partition of hole and particle spaces. These results are tested and confirmed for the pairing model, neutron matter, and finite nuclei.