The vortex charge in high-temperature superconductors was investigated. It was found that the vortex charge was negative when a sufficient strength of antiferromagnetic (AF) order was induced inside the vortex core. The vortex charge at optimal doping was studied as a function of magnetic field. The results showed that the AF order was absent inside the vortex core for small Coulomb repulsion.published_or_final_versio
