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Semiclassical theory of shot noise in disordered SN contacts

K. E. Nagaev·M. Buttiker
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Abstract

We present a semiclassical theory of shot noise in diffusive superconductor - normal metal contacts. At subgap voltages, we reproduce the doubling of shot noise with respect to conventional normal-metal contacts, which is interpreted in terms of an energy balance of electrons. Above the gap, the voltage dependence of the noise crosses over to the standard one with a voltage-independent excess noise. The semiclassical description of noise leads to correlations between currents at different electrodes of multiterminal SN contacts which are always of fermionic type, i.e. negative. Using a quantum extension of the Boltzmann - Langevin method, we reproduce the peculiarity of noise at the Josephson frequency and obtain an analytical frequency dependence of noise at above-gap voltages.

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K. E. Nagaev, M. Buttiker. 2000-07-07. Semiclassical theory of shot noise in disordered SN contacts. https://doi.org/10.1103/physrevb.63.081301

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