Boundary Effects and the Order Parameter Symmetry in High-Tc Superconductors

Abstract

Apparently conflicting phase-sensitive measurements of the order parameter symmetry in the high-T${}_c$ superconductors may be explained by regions near surfaces in which the order parameter symmetry is different than in the bulk. These surface states can lead to interesting and testable effects.

4 pages, revtex, 3 postscript figures