Spin-polarized neutron matter: Critical unpairing and BCS-BEC precursor

Abstract

We obtain the critical magnetic field required for complete destruction of $S$-wave pairing in neutron matter, thereby setting limits on the pairing and superfluidity of neutrons in the crust and outer core of magnetars. We find that for fields $B\ge 10^{17}$ G the neutron fluid is non-superfluid -- if weaker spin-1 superfluidity does not intervene -- a result with profound consequences for the thermal, rotational, and oscillatory behavior of magnetars. Because the dineutron is not bound in vacuum, cold dilute neutron matter cannot exhibit a proper BCS-BEC crossover. Nevertheless, owing to the strongly resonant behavior of the $nn$ interaction at low densities, neutron matter shows a precursor of the BEC state, as manifested in Cooper-pair correlation lengths {being} comparable to the interparticle distance. We make a systematic quantitative study of this type of BCS-BEC crossover in the presence of neutron fluid spin-polarization induced by an ultra-strong magnetic field. We evaluate the Cooper pair wave-function, quasiparticle occupation numbers, and quasiparticle spectra for densities and temperatures spanning the BCS-BEC crossover region. The phase diagram of spin-polarized neutron matter is constructed and explored at different polarizations.

13 RevTex pages, 18 figures, v2: minor changes, references added, matches published version

References in corpus (7)

• BCS-BEC crossover of neutron pairs in symmetric and asymmetric nuclear matter
• Magnetar superconductivity versus magnetism: neutrino cooling processes
• BCS-BEC crossovers and unconventional phases in dilute nuclear matter
• Phase diagram of dilute nuclear matter: Unconventional pairing and the BCS-BEC crossover
• BCS-BEC crossover in nuclear matter with the relativistic Hartree-Bogoliubov theory
• Dineutron correlations and BCS-BEC crossover in nuclear matter with the Gogny pairing force
• Critical Zeeman Splitting of a Unitary Fermi Superfluid

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