抄録
We consider a model d-wave superconductor in which the Y2± 2 states have the highest transition temperature and the Y2± 1 states have a slightly lower transition temperature and show that this model has a nonuniform phase just below the upper critical field in a wide temperature range. The nonuniform state is due to the mixing between the Y2, ± 2 state and the Y2, ± 1 state under magnetic field and has a spatially oscillating order parameter like the Fulde-Ferrell state but has a different character from the Fulde-Ferrell state because this nonuniform state is induced by the orbital magnetic effect. The relevance of the model to a heavy Fermion superconductor UPd2Al3 is mentioned.