Development of an Array of Kinetic Inductance Magnetometers (KIMs)

TL;DR

This paper presents the development and optimization of a cryogenic kinetic inductance magnetometer (KIM) that uses superconducting nanowires, offering a multiplexed, sensitive alternative to SQUIDs for various scientific applications.

Contribution

The paper introduces a novel KIM design utilizing nonlinear kinetic inductance in superconducting nanowires with multiplexed readout capabilities, replacing traditional SQUIDs.

Findings

Demonstrated a functional KIM with flux sensitivity.

Achieved frequency multiplexing in the readout.

Potential applications in astrophysics and medical imaging.

Abstract

We describe optimization of a cryogenic magnetometer that uses nonlinear kinetic inductance in superconducting nanowires as the sensitive element instead of a superconducting quantum interference device (SQUID). The circuit design consists of a loop geometry with two nanowires in parallel, serving as the inductive section of a lumped LC resonator similar to a kinetic inductance detector (KID). This device takes advantage of the multiplexing capability of the KID, allowing for a natural frequency multiplexed readout. The Kinetic Inductance Magnetometer (KIM) is biased with a DC magnetic flux through the inductive loop. A perturbing signal will cause a flux change through the loop, and thus a change in the induced current, which alters the kinetic inductance of the nanowires, causing the resonant frequency of the KIM to shift. This technology has applications in astrophysics, material science, and the medical field for readout of Metallic Magnetic Calorimeters (MMCs), axion detection, and magnetoencephalography (MEG).