Organic conductors are layered, correlated electron systems known to stabilize a remarkable diversity of ground states simply by tuning the kinetic to potential energy ratio. Accomplished by means of applied mechanical or chemical pressure, the accessible phases range from quantum disordered Mott insulators to strange metals and unconventional superconductors. Here we examine a novel field-induced superconducting phase, stabilized when the magnetic field is applied strictly in-plane. In this configuration, the usual flux-vortex driven transition is avoided, and the important magnetic coupling is through the Zeeman effect. A consequence is the novel observation of an otherwise quite elusive phase, predicted in the 1960's by Fulde and Ferrell, and by Larkin and Ovchinnikov. Various transport, thermodynamic, and NMR evidence for the so-called FFLO state is presented, and a re-drawing of the field-temperature phase diagram in the presence of disorder is proposed.
Seminar Speaker: Stuart Brown, UCLA
Host: Halperin
Keywords: Physics, Astronomy, Seminar, Colloquium