Superfluidity in nuclear systems and neutron stars

TL;DR

This paper reviews microscopic theories and methods for understanding superfluidity in nuclear matter and neutron stars, focusing on pairing mechanisms, quantum states, and their astrophysical implications.

Contribution

It provides a comprehensive survey of quantum many-body techniques applied to nuclear superfluids and discusses recent progress in microscopic understanding of superfluid properties in neutron-star environments.

Findings

Progress in quantitative understanding of nucleonic superfluid properties

Analysis of pairing mechanisms in neutron-star matter

Insights into quantum vortex dynamics in nuclear superfluids

Abstract

Nuclear matter and finite nuclei exhibit the property of superfluidity by forming Cooper pairs. We review the microscopic theories and methods that are being employed to understand the basic properties of superfluid nuclear systems, with emphasis on the spatially extended matter encountered in neutron stars, supernova envelopes, and nuclear collisions. Our survey of quantum many-body methods includes techniques that employ Green functions, correlated basis functions, and Monte Carlo sampling of quantum states. With respect to empirical realizations of nucleonic and hadronic superfluids, this review is focused on progress that has been made toward quantitative understanding of their properties at the level of microscopic theories of pairing, with emphasis on the condensates that exist under conditions prevailing in neutron-star interiors. These include singlet $S$-wave pairing of neutrons in the inner crust, and, in the quantum fluid interior, singlet-$S$ proton pairing and triplet coupled $P$-$F$-wave neutron pairing. Additionally, calculations of weak-interaction rates in neutron-star superfluids within the Green function formalism are examined in detail. We close with a discussion of quantum vortex states in nuclear systems and their dynamics in neutron-star superfluid interiors.