Josephson effect in Fulde-Ferrell-Larkin-Ovchinnikov superconductors

Because of the difference in the momenta of the superconducting order param eters, the Josephson current in a Josephson junction between a Fulde-Ferrel l-Larkin-Ovehinnikov (FFLO) superconductor and a conventional BCS supercond uctor is suppressed. We show that the Josephson current may he recovered by applying a magnetic field in the junction. The field strength and directio n at which the supercurrent recovery occurs depend upon the momentum and st ructure of the order parameter in the FFLO stare. Thus the Josephson effect provides an unambiguous way to detect the existence of an FFLO state, and to measure the momentum of the order parameter.