Phase diagram and superconducting density of states of the quasi-two-dimensional d-wave superconductor in parallel magnetic field
We report on results of a theoretical study of the d-wave Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state. A complete temperature vs. magnetic field phase diagram for a model system is obtained. This phase diagram comprises the normal phase, the zero-momentum pairing BCS phase and two types of FFLO phases. The magnetic-field variation of the superconducting density of states, NS(varpi), is studied systematically. In the FFLO phase, we find a characteristic multi-peak structure in NS(varpi), followed by its unique evolution. These highly distinctive features enable us to discriminate between the d-wave FFLO state and other types of superconducting states.