Particle-hole coherence in superfluid 3He and in superconductors

Particle-hole coherence and Andreev scattering are discussed in the framework of a quasiclassical density matrix description both in systems with conventional as well as with unconventional pairing. The quasi-classical formulation allows one to study the consequences of anisotropy, impurity scattering, inelastic scattering, interface roughness, and other effects which may be important in analyzing Andreev-scattering experiments in less than ideal circumstances. (author). 7 figs., 22 refs