Long-Range Coherence in a Mesoscopic Metal near a Superconducting Interface

H. Courtois; Ph. Gandit; D. Mailly; B. Pannetier

doi:10.1103/PhysRevLett.76.130

Long-Range Coherence in a Mesoscopic Metal near a Superconducting Interface

H. Courtois, Ph. Gandit, D. Mailly, and B. Pannetier

Phys. Rev. Lett. 76, 130 – Published 1 January 1996

Abstract

We identify the different contributions to quantum interference in a mesoscopic metallic loop in contact with two superconducting electrodes. At low temperature, a flux-modulated Josephson coupling is observed with strong damping over the thermal length $L_{T}$ . At higher temperature, the magnetoresistance exhibits $h / 2 e$ -periodic oscillations with $1 / T$ power law decay. This flux-sensitive contribution arises from coherence of low-energy quasiparticle states over the phase-breaking length $L_{ϕ}$ . Mesoscopic fluctuations contribute as a small $h / e$ oscillation, resolved only in the purely normal state.

Received 5 July 1995

DOI:https://doi.org/10.1103/PhysRevLett.76.130

Authors & Affiliations

H. Courtois¹, Ph. Gandit¹, D. Mailly², and B. Pannetier¹

¹Centre de Recherches sur les Très Basses Températures, CNRS (Associé à l'Université Joseph Fourier), 25 Avenue des Martyrs, 38042 Grenoble, France
²Laboratoire de Microstructures et de Microélectronique, CNRS, 196 Avenue H. Ravera, 92220 Bahneux, France