Defective Vortex Lattices in Layered Superconductors with Both Point and Correlated Pins

The mixed phase of layered superconductors with no magnetic screening is studied through a partial duality analysis of the corresponding XY model in the presence of random pinning centers. Sufficiently weak Josephson coupling between adjacent layers results in an entangled vortex solid that exhibits weak superconductivity across layers. The corresponding vortex liquid state shows an inverted specific heat anomaly that is a precursor to the weak superconductor.