Mixed state in magnetic superconductors

The boson theory is reformulated in a form applicable to the mixed state in the rare-earth compounds, RRh₄B₄, RₓMo₆S₈, and RₓMo₆Se₆. The magnetic field induced by the persistent current of vortices, and the spin magnetization magnetized by this field are self-consistently calculated. A nonuniform spin magnetization with the periodicity of a flux-line lattice appears in the crystals. The total flux which is the sum of the spin and current contributions is quantized. This quantization effects the current inversion and thus the attractive interaction between the vortices. The calculated magnetization has a tendency of becoming the type-I or type II-1 superconductor even for a large κ. The fact that Hc2 is drastically depressed near the Curie or N\`eel temperature explains the experiments on DyₓMo₆S₈ and ErₓMo₆S₈.