Synchronized Andreev Transmission in Chains of SNS Junctions

Abstract

Abstract. We construct a nonequilibrium theory for the charge transfer through a diffusive array of alternating normal (N) and superconducting (S) islands comprising an SNSNS junction, with the size of the central S-island being smaller than the energy relaxation length. We demonstrate that in the nonequilibrium regime the central island acts as Andreev retransmitter with the Andreev conversions at both NS interfaces of the central island correlated via over-the-gap transmission and Andreev reflection. This results in a synchronized transmission at certain resonant voltages which can be experimentally observed as a sequence of spikes in the differential conductivity.

Nonequilibrium mesoscopic superconductors in a fluctuational regime

“…where H is the magnetic field and η = 1/10 for a spherical island. Nonequilibrium fluctuation corrections to other quantities, e.g, related to the diffusion propagator contributions to Z [and the Langevin noise corrections with the correlator proportional T * ], will be presented in [18]. Now we sketch a general procedure for calculating fluctuation-related quantities.…”

“…The Ginsburg-Landau expansion of the effective thermodynamical potential is an example of the so-called low energy field theory, i. The fluctuations of the ∆-field enter the collision integrals of the kinetic equations and the collisionless terms [the fluctuation renormalizations of the KE-coefficients], while ∆ 1 enter the (nonlinear) kinetic equations as external fields [4,18]. The ∆-fluctuations in KE contribute to the fluctuation corrections to the kinetic coefficients [18].…”

“…The fluctuations of the ∆-field enter the collision integrals of the kinetic equations and the collisionless terms [the fluctuation renormalizations of the KE-coefficients], while ∆ 1 enter the (nonlinear) kinetic equations as external fields [4,18]. The ∆-fluctuations in KE contribute to the fluctuation corrections to the kinetic coefficients [18]. The ∆ 1 -terms in KE are important while Fǫ differs essentially from tanh(ǫ/2T ) only at small energies, ǫ ∼ ∆ 1 .…”

Analytical description of the quantum-mesoscopic-classical transition in systems with quasidiscrete environments

“…It is worth noting that condition (20) is sufficient but not necessary. Even beyond the limitations set by condition (20) the envelop function Eq. (18) usually still approximates Θ quite well.…”

“…Our consideration for the condensation of the δfunctions in Eq. (1) can be extended to the more general case of arbitrary weights P n > 0 which decay quickly with n [20]. In this case, the time representation of I would consist of quasi-periodic functions as well and the topological argument of the path covering a torus surface densely would be applicable again.…”