Conductance enhancement in quantum point contact-semiconductor-superconductor devices

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dc.creatorMortensen, Niels Asger
dc.creatorJauho, Antti-Pekka
dc.creatorFlensberg, Karsten
dc.creatorSchomerus, Henning
dc.date1999-03-12
dc.date1999-07-29
dc.date.accessioned2026-07-07T03:13:01Z
dc.date.available2026-07-07T03:13:01Z
dc.descriptionWe 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-two enhancement of the conductance G_NS compared to the normal state conductance G_N 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-two enhancement which may explain the absence of conductance enhancement in experiments on metal-superconductor structures.
dc.description9 pages, 6 figures. Comments and 2 references added
dc.identifierhttps://arxiv.org/abs/cond-mat/9903205
dc.identifierhttp://arxiv.org/abs/cond-mat/9903205
dc.identifierPhys. Rev. B 60, 13762 (1999).
dc.identifierdoi:10.1103/PhysRevB.60.13762
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/29137
dc.subjectSuperconductivity
dc.subjectMesoscale and Nanoscale Physics
dc.titleConductance enhancement in quantum point contact-semiconductor-superconductor devices
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