  A characteristic feature of the BCS theory of superconductivity is the
quantum-mechanical coherence of particle and hole states. Direct observation of
particle-hole coherence in unusual superconducting materials is a strong
indication of traditional superconductivity. We use the Fermi liquid theory of
superconductivity to study the implications of particle-hole coherence on
properties of d-wave superconductors near surfaces. Typical surface phenomena
are the suppression of the superconducting order parameter, surface bound
states associated with Andreev reflection, anomalous screening currents, and
spontaneous breaking of time-reversal symmetry. We review these phenomena and
present new results for the effects of surface roughness.
