title: Negative length orbits in normal-superconductor billiard systems
abstract: The path-length spectra of mesoscopic systems including diffractive scatterers and connected to a superconductor are studied theoretically. We show that the spectra differ fundamentally from that of normal systems due to the presence of Andreev reflection. It is shown that negative path lengths should arise in the spectra as opposed to the normal system. To highlight this effect we carried out both quantum mechanical and semiclassical calculations for the simplest possible diffractive scatterer. The most pronounced peaks in the path-length spectra of the reflection amplitude are identified by the routes that the electron and/or hole travels.
authors.affiliation: Eotvos University, Department of Physics of Complex Systems, H-1117 Budapest, Pazmany Peter setany 1/A, Hungary.
authors.initials: J
authors.lastname: Cserti
authors.initials: G
authors.lastname: Vattay
authors.initials: J
authors.lastname: Koltai
authors.initials: F
authors.lastname: Taddei
authors.initials: CJ
authors.lastname: Lambert