Nonlocality in mesoscopic Josephson junctions with strip geometry

TL;DR

This paper investigates how nonlocal electrodynamics affects the current distribution and critical current periodicity in mesoscopic Josephson junctions with strip geometry, revealing boundary effects and comparing with experimental data.

Contribution

It introduces a detailed analysis of nonlocal effects on current patterns and flux periodicity in Josephson junctions, highlighting the role of geometry and boundary conditions.

Findings

Critical current periodicity depends on the ratio of vortex distance to nonlocal range.

Double periodicity emerges for strong nonlocality due to boundary effects.

Theoretical results align well with recent experimental observations.

Abstract

We study the current in a clean superconductor-normal-metal-superconductor junction of length d and width w in the presence of an applied magnetic field H. We show that both the geometrical pattern of the current density and the critical current as a function of the total flux in the junction, depend on the ratio of the Josephson vortex distance a_0 and the range r of the nonlocal electrodynamics. In particular, the critical current has the periodicity of the superconducting flux quantum only for r<a_0 and acquires, due to boundary effects, the double (pseudo-) periodicity for strong nonlocality, r>a_0. Comparing our results to recent experiments of Heida et al. [Phys. Rev. B 57, R5618 (1998)] we find good agreement.