Mixed lattice phases in cold dense matter

Abstract

Over a wide density range, the ground state of cold neutral matter in the absence of external magnetic fields is a degenerate sea of electrons containing a lattice of nuclei. In certain density regions, a phase composed of interpenetrating cubic lattices of different nuclides is preferable to a body-centered cubic lattice of any single nuclide. The arguments supporting this result are first made assuming the electrons to be a uniform background; the qualitative features remain when screening and exchange effects are included.