Vortex state in a Fulde-Ferrell-Larkin-Ovchinnikov superconductor based on quasiclassical theory

We investigate the vortex state with Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) modulations suggested for a high-field phase of CeCo In5. On the basis of quasiclassical Eilenberger theory, we calculate the three-dimensional structure of pair potentials, internal magnetic fields, paramagnetic moments, and electronic states for s -wave and d -wave pairings comparatively. The π -phase shift of the pair potential at the FFLO nodal plane or at the vortex core induces sharp peak states in the local density of states and enhances the local paramagnetic moment. We also discuss the NMR spectrum and neutron scattering as methods to detect the FFLO structure.