Toward electrodynamics of unconventional phases of dilute nuclear matter

TL;DR

This paper explores the unconventional superconducting phases of dilute nuclear matter, analyzing their electromagnetic responses and identifying the conditions under which they behave as type-II superconductors with vortex formations.

Contribution

It provides a detailed evaluation of the Ginzburg-Landau parameter across the phase diagram, revealing the nature of these phases as type-II superconductors and their vortex characteristics.

Findings

Unconventional phases are good type-II superconductors.

These phases form Abrikosov vortices with twice the magnetic flux quantum.

LOFF phase is near the transition to type-I, close to the critical GL parameter.

Abstract

The phase diagram of isospin-asymmetrical nuclear matter may feature a number of unconventional phases, which include the translationally and rotationally symmetric, but isospin-asymmetrical BCS condensate, the current-carrying Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase, and the heterogeneous phase-separated phase. Because the Cooper pairs of the condensate carry a single unit of charge, these phases are charged superconductors and respond to electromagnetic gauge fields by either forming domains (type-I superconductivity) or quantum vortices (type-II superconductivity). We evaluate the Ginzburg-Landau (GL) parameter across the phase diagram and find that the unconventional phases of isospin-asymmetrical nuclear matter are good type-II superconductors and should form Abrikosov vortices with twice the quantum of magnetic flux. We also find that the LOFF phase at the boundary of the transition to the type-I state, with the GL parameter being close to the critical value $1/\sqrt{2}$.