Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 8/02/1993 |
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<mark>Journal</mark> | Journal of Physics: Condensed Matter |
Issue number | 6 |
Volume | 5 |
Number of pages | 10 |
Pages (from-to) | 707-716 |
Publication Status | Published |
<mark>Original language</mark> | English |
By computing Andreev scattering coefficients for a three-dimensional disordered solid containing superconducting inclusions and evaluating a generalized Landauer-Buttiker formula for the two-probe electrical conductance G, an intuitive result is obtained for the dependence of G on the phase of the superconductors. For the simplest case of two inclusions, it is shown that G varies periodically with the phase difference phi of the superconducting islands, with period 2pi. For more than two inclusions, beating can occur. It the superconductors are decoupled, G varies periodically with time, at the Josephson frequency. If the superconductors are weakly coupled, this behaviour is preceded by a time-independent regime in which phi increases with the externally applied voltage, while G changes non-monotonically. It is demonstrated that at least in the presence of single-channel external leads, the ensemble averaged conductance of a highly disordered system varies periodically with period 2pi, in contrast with a periodicity of pi found for weakly localized systems.