Lattice effects on the current-voltage characteristics of superconducting arrays

TL;DR

This paper investigates how the discrete lattice structure influences the current-voltage behavior of 2D superconducting Josephson junction arrays, revealing effects mainly at intermediate currents where lattice potentials are comparable to vortex-pair unbinding barriers.

Contribution

It provides a detailed calculation of lattice potential energies for various geometries and directions, clarifying when lattice effects become significant in the array's electrical response.

Findings

Lattice effects are negligible at low and high currents.

Lattice potential becomes significant at intermediate currents.

Lattice effects may influence the current-voltage characteristics at certain current levels.

Abstract

The lattice effects on the current-voltage characteristics of two-dimensional arrays of resistively shunted Josephson junctions are investigated. The lattice potential energies due to the discrete lattice structure are calculated for several geometries and directions of current injection. We compare the energy barrier for vortex-pair unbinding with the lattice pinning potential, which shows that lattice effects are negligible in the low-current limit as well as in the high-current limit. At intermediate currents, on the other hand, the lattice potential becomes comparable to the barrier height and the lattice effects may be observed in the current-voltage characteristics.