A one-dimensional tunable magnetic metamaterial

TL;DR

This paper demonstrates a one-dimensional superconducting metamaterial composed of SQUIDs with tunable resonance frequencies, allowing in situ control of its magnetic properties over a broad frequency range.

Contribution

It introduces a tunable magnetic metamaterial using a chain of SQUIDs and a novel method to extract effective permeability from transmission data.

Findings

Achieved broad frequency tunability of the metamaterial

Demonstrated in situ control of magnetic response

Validated extraction technique for effective parameters

Abstract

We present experimental data on a one-dimensional superconducting metamaterial that is tunable over a broad frequency band. The basic building block of this magnetic thin-film medium is a single-junction (rf-) superconducting quantum interference device (SQUID). Due to the nonlinear inductance of such an element, its resonance frequency is tunable in situ by applying a dc magnetic field. We demonstrate that this results in tunable effective parameters of our metamaterial consisting of 54 SQUIDs. In order to obtain the effective magnetic permeability from the measured data, we employ a technique that uses only the complex transmission coefficient S21.