The role of coupling radius in 1D and 2D SQUID and SQIF arrays

TL;DR

This paper explores how the coupling radius affects the transfer function in 1D and 2D SQUID and SQIF arrays, revealing its dependence on impedance and independence from the number of junctions in series.

Contribution

It introduces the concept of coupling radius in SQUID arrays and analyzes its dependence on impedance and array configuration.

Findings

Plateauing of maximum transfer function with increasing junctions in parallel.

Coupling radius increases as normalized impedance decreases.

Coupling radius is independent of the number of junctions in series.

Abstract

We investigate theoretically the effect of the coupling radius on the transfer function in 1D and 2D SQUID arrays with different number of Josephson junctions in parallel and series at 77 K. Our results show a plateauing of the array maximum transfer function with the number of junctions in parallel. The plateauing defines the array coupling radius which we show increases with decreasing the normalised impedance of the SQUID loop inductance. The coupling radius is found to be independent of the number of junctions in series. Finally, we investigate the voltage versus magnetic field response and maximum transfer function of one 1D and two 2D SQIF arrays with different SQUID loop area distributions.