1999/03/31 by Niels Asger Mortensen, Antti-Pekka Jauho, Antti‐Pekka Jauho +2 · 1 citation
Engineering · Physics and Astronomy · #Molecular Junctions and Nanostructures #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.60.13762
published as Phys. Rev. B 60, 13762 (1999). · 9 pages, 6 figures. Comments and 2 references added
arxiv created 1999/07/29 · openalex publication_date 1999/11/15 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present numerical calculations of the conductance of an interface between a phase-coherent two-dimensional electron gas and a superconductor with a quantum point contact in the normal region. Using a scattering matrix approach we reconsider the geometry of De Raedt, Michielsen, and Klapwijk [Phys. Rev. B 50, 631 (1994)] which was studied within the time-dependent Bogoliubov--de Gennes formalism. We find that the factor-of-2 enhancement of the conductance GNS compared to the normal state conductance GN for ideal interfaces may be suppressed for interfaces with a quantum point contact with only a few propagating modes. The suppression is found to depend strongly on the position of the Fermi level. We also study the suppression due to a barrier at the interface and find an anomalous behavior caused by quasiparticle interference. Finally, we consider the limit of sequential tunneling and find a suppression of the factor-of-2 enhancement which may explain the absence of conductance enhancement in experiments on metal-superconductor structures.