Glassy quantum nuclear pasta in neutron star crusts

Abstract

Nuclear pasta is an exotic form of nuclear matter that occurs in the crust of neutron stars below saturation density. Various exotic nuclear structures with cylindrical, planar, and more complicated geometries evolve from the Coulomb lattice of nuclei immersed in a fluid of neutrons. Such structures in the crust should not only affect how a neutron star cools and rotates but also the height of the ``mountains'' that the crust can sustain---potentially detectable as persistent sources of gravitational waves. By performing a large set of quantum calculations the authors show that the energy landscape of nuclear pasta consists of multiple local minima with very similar energies. Hence, at the characteristic temperatures nuclear pasta becomes a self-organized glassy amorphous solid similar to soft-matter systems found on Earth.