Effects of magnetic field on two-dimensional Superconducting Quantum Interference Filters

TL;DR

This study investigates how magnetic fields influence 2D superconducting quantum interference filters, revealing their potential as sensitive detectors for magnetic field gradients due to their unique voltage responses.

Contribution

It provides the first detailed experimental analysis of 2D-SQIFs' magnetic field dependence and demonstrates their application in detecting magnetic field gradients.

Findings

Voltage dip at B=0 depends on loop area distribution and bias current.

Voltage span scales with the number of operating rows.

Sensitivity to field gradients enables use as spatial magnetic sensors.

Abstract

We present an experimental study of two-dimensional superconducting quantum interference filters (2D-SQIFs) in the presence of a magnetic field B. The dependences of the dc voltage on the applied magnetic field are characterized by a unique delta-like dip at B=0, which depends on the distribution of the areas of the individual loops, and on the bias current. The voltage span of the dip scales proportional to the number of rows simultaneously operating at the same working point. In addition, the voltage response of the 2D-SQIF is sensitive to a field gradient generated by a control line and superimposed to the homogeneous field coil. This feature opens the possibility to use 2D superconducting quantum interference filters as highly sensitive detectors of spatial gradients of magnetic field.