Vortex liquid in magnetic-field-induced superconducting vacuum of quenched lattice QCD

TL;DR

This paper demonstrates through lattice QCD simulations that a strong magnetic field induces a vortex liquid phase in the QCD vacuum, characterized by inhomogeneous rho meson condensates and a smooth phase transition.

Contribution

It provides the first numerical evidence of a vortex liquid phase in quenched lattice QCD under strong magnetic fields, revealing inhomogeneous rho condensates and vortex structures.

Findings

Rho vortices form a liquid in quenched QCD under strong magnetic fields.

The phase transition from insulator to vortex liquid is very smooth.

Numerical simulations confirm the presence of inhomogeneous rho meson condensates.

Abstract

In the background of the strong magnetic field the vacuum is suggested to possess an electromagnetically superconducting phase characterised by the emergence of inhomogeneous quark-antiquark vector condensates which carry quantum numbers of the charged rho mesons. The rho-meson condensates are inhomogeneous due to the presence of the stringlike defects ("the rho vortices") which are parallel to the magnetic field (the superconducting vacuum phase is similar to the mixed Abrikosov phase of a type-II superconductor). In agreement with these expectations, we have observed the presence of the rho vortices in numerical simulations of the vacuum of the quenched two-color lattice QCD in strong magnetic field background. We have found that in the quenched QCD the rho vortices form a liquid. The transition between the usual (insulator) phase at low B and the superconducting vortex liquid phase at high B turns out to be very smooth, at least in the quenched QCD.