Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1817697 | Physica C: Superconductivity and its Applications | 2014 | 5 Pages |
•The energy levels are indicated by the minima peaks of the conductance spectra.•The quality of the junctions can be identified by the conductance spectra.•The potential strengths at the interfaces are set to be unequal.
We present a theory for particle transport in a metal/superconductor/metal (MSM) double junction system. For comparison, we considered either an s -wave or dx2-y2dx2-y2-wave superconductor sandwiched by two metals in a two dimensional system. The calculation was done by extending the theory of the Blonder, Tinkham, and Klapwijk (BTK) formulation, after which the transport probabilities and electronic conductance spectra were calculated. The dispersions used in this work were treated within a free electron approximation. At the two interfaces, the interfacial scattering was set to be distinguishable. As a result, it was found that the spectra gave us useful information to determine the quality of the double junction. That is, the conductance spectra in the region of E<ΔE<Δ are affected by the potential strength at the first interface, while there is a slight affect form the potential at the second interface. When E>ΔE>Δ, the spectra of both types of superconductors behave indifferently with changes in the potential strength. Moreover, the dependence of the conductance spectra on the crystallographic orientation and the thickness of the superconducting layer are clearly analyzed in this work.