NATURE OF ORBITAL-GLASS TRANSITION IN D-WAVE CERAMIC SUPERCONDUCTORS

A close connection is pointed out between the orbital-glass state recently proposed for high-T-c, ceramic superconductors and the chiral-glass state identified in XY spin glasses. Based on this analogy, the orbital-glass state is argued to be an equilibrium phase with broken reflection (charge-conjugation) symmetry, but not a true superconductor on long length and time scales. The transition to the normal state lies in the universality class of the 3d Ising spin glass. It is predicted that the nonlinear susceptibility in the zero-field limit exhibits a negative divergence for d-wave ceramics and a positive divergence for s-wave ceramics.