2003/02/28 by Erhai Zhao, Tomas Lofwander, J. A. Sauls
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.91.077003
published as Phys. Rev. Lett. 91, 077003 (2003) [URL: http://link.aps.org/abstract/PRL/v91/e077003] · 4 pages, 3 figures Expanded discussion of boundary conditions for Ricatti amplitudes
arxiv created 2003/09/02 · arxiv updated 2009/11/30
We present a theory for quasiparticle heat transport through superconducting weak links. The thermal conductance depends on the phase difference (ϕ) of the superconducting leads. Branch conversion processes, low-energy Andreev bound states near the contact and the suppression of the local density of states near the gap edge are related to phase-sensitive transport processes. Theoretical results for the influence of junction transparency, temperature and disorder, on the phase modulation of the conductance are reported. For high-transmission weak links, D→ 1, the formation of an Andreev bound state at ε\tiny b=Δcos(ϕ/2) leads to suppression of the density of states for the continuum excitations that transport heat, and thus, to a reduction in the conductance for ϕ≃π. For low-transmission (D≪ 1) barriers resonant scattering at energies ε≃(1+D/2)Δ leads to an increase in the thermal conductance as T drops below Tc (for phase differences near ϕ=π).