Phases of asymmetric nuclear matter with broken space symmetries
Abstract
Isoscalar Cooper pairing in isospin asymmetric nuclear matter occurs between states populating two distinct Fermi surfaces, each for neutrons and protons. The transition from a BCSlike to the normal (unpaired) state, as the isospin asymmetry is increased, is intervened by superconducting phases which spontaneously break translational and rotational symmetries. One possibility is the formation of a condensate with a periodic crystallinelike structure where Cooper pairs carry net momentum (the nuclear LarkinOvchinnikovFuldeFerrell phase). Alternatively, perturbations of the Fermi surfaces away from spherical symmetry allow for minima in the condensate free energy which correspond to states with quadrupole deformations of Fermi surfaces and zero momentum of the Cooper pairs. In a combined treatment of these phases we show that, although the Cooper pairing with finite momentum might arise as a local minimum, the lowest energy state features are deformed Fermi surfaces and Cooper pairs with vanishing total momentum.
 Publication:

Physical Review C
 Pub Date:
 January 2003
 DOI:
 10.1103/PhysRevC.67.015802
 arXiv:
 arXiv:nuclth/0209061
 Bibcode:
 2003PhRvC..67a5802M
 Keywords:

 21.65.+f;
 21.30.Fe;
 26.60.+c;
 Nuclear matter;
 Forces in hadronic systems and effective interactions;
 Nuclear matter aspects of neutron stars;
 Nuclear Theory
 EPrint:
 22 pages, 6 figures, RevTex