Abstract
We calculate the transmission of electrons and holes between two normal-metal (N) electrodes, separated over a distance by an impurity-free superconductor (S) with -wave symmetry of the order parameter. Nodal lines of vanishing excitation gap form ballistic conduction channels for coupled electron-hole excitations, described by an anisotropic two-dimensional Dirac equation. We find that the transmitted electrical and thermal currents both have the pseudodiffusive scaling characteristic of massless Dirac fermions—regardless of the presence of tunnel barriers at the NS interfaces. Tunnel barriers reduce the slope of the scaling in the case of the electrical current while leaving the thermal current unaffected.
- Received 29 September 2009
DOI:https://doi.org/10.1103/PhysRevB.80.224517
©2009 American Physical Society
Synopsis
Dirac connection
Published 4 January 2010
Ballistic electron transport through a clean superconductor with d-wave symmetry has features in common with graphene.
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