Spontaneous electromagnetic superconductivity and superfluidity of QCD×QED vacuum in strong magnetic field

Abstract

It was recently shown that the vacuum in the background of a strong enough magnetic field may become an electromagnetic superconductor due to interplay between strong and electromagnetic forces. The superconducting ground state of the QCD×QED sector of the vacuum is associated with magnetic-field- assisted emergence of quark-antiquark condensates which carry quantum numbers of charged ρ mesons (i.e., of electrically charged vector particles made of lightest, u and d, quarks and antiquarks). Here we demonstrate that this exotic electromagnetic superconductivity of vacuum is also accompanied by even more exotic superfluidity of the neutral ρ mesons. The superfluid component - despite being electrically neutral - turns out to be sensitive to an external electric field as the superfluid may ballistically be accelerated by a test background electric field along the magnetic-field axis. In the ground state both superconducting and superfluid components are inhomogeneous periodic functions of the transversal (with respect to the axis of the magnetic field) spatial coordinates. The superconducting part of the ground state resembles an Abrikosov ground state in a type-II superconductor: the superconducting condensate organizes itself in periodic structure which possesses the symmetry of an equilateral triangular lattice. Each elementary lattice cell contains a stringlike topological defect (superconductor vortex) in the charged ρ condensates as well as three superfluid vortices and three superfluid antivortices made of the neutral ρ condensate. The superposition of the superconductor and superfluid vortex lattices has a complicated "kaleidoscopic" pattern. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.