Entanglement in condensates involving strong interactions

TL;DR

This paper investigates entanglement entropy in strongly interacting condensed matter systems, specifically in high-density quark matter, comparing BCS superconductivity and Bose-Einstein condensation of quark pairs, revealing entropy dependencies on interaction parameters.

Contribution

It introduces a comparative analysis of entanglement entropy in BCS and BEC models with strong interactions in quark matter, highlighting the role of energy gaps and short-range interactions.

Findings

Entropy depends on the energy gap in BCS superconductivity.

Ground state entropy dominates at low and high momenta.

Entropy in BEC depends on short-range repulsive interactions.

Abstract

We look at two well known examples of interacting systems relating to condensed matter in which we put the strong interacting parameters. At high quark chemical potentials and low temperatures we study the entropy arising from the excitation in the BCS model of superconductivity and the Bose-Einstein condensation (BEC) of colored quark pairs. We compare it with the ground state entropy for a system consisting of two colored quarks. In the BCS model we found that the entropy strongly depends on the energy gap. Both for the very small values of the momenta as well as those much greater than the characterizing Fermi momentum $p_f$, the ground state entropy is dominant. For the BEC case we suggest a phenomenological model to build up colored bosonic quark pairs. Here the entropy entirely depends upon the short ranged repulsive interactions between the quark pairs and vanishes for large momenta.