2007/09/30 by Mark G. Alford, Mark Alford, Krishna Rajagopal +3 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #High-pressure geophysics and materials #Quantum, superfluid, helium dynamics #astro-ph #cond-mat.supr-con #hep-ph #nucl-th
paper · pdf · doi:10.1103/revmodphys.80.1455
published as Rev.Mod.Phys.80:1455-1515,2008 · 63 pages, v2: version to appear in Rev. Mod. Phys.; references added; small improvements at various points
arxiv created 2008/01/21 · openalex publication_date 2008/11/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Matter at high density and low temperature is expected to be a color superconductor, which is a degenerate Fermi gas of quarks with a condensate of Cooper pairs near the Fermi surface that induces color Meissner effects. At the highest densities, where the QCD coupling is weak, rigorous calculations are possible, and the ground state is a particularly symmetric state, the color-flavor locked (CFL) phase. The CFL phase is a superfluid, an electromagnetic insulator, and breaks chiral symmetry. The effective theory of the low-energy excitations in the CFL phase is known and can be used, even at more moderate densities, to describe its physical properties. At lower densities the CFL phase may be disfavored by stresses that seek to separate the Fermi surfaces of the different flavors, and comparison with the competing alternative phases, which may break translation and/or rotation invariance, is done using phenomenological models. We review the calculations that underlie these results and then discuss transport properties of several color-superconducting phases and their consequences for signatures of color superconductivity in neutron stars.