A Non-Foster Superconducting Broadband Matching Network

TL;DR

This paper introduces a Josephson junction-based broadband impedance matching circuit that enhances axion dark matter detection by overcoming traditional gain-bandwidth limitations, enabling faster and more sensitive searches.

Contribution

It proposes a novel impedance matching network using a Josephson junction to improve the bandwidth and sensitivity of axion detectors.

Findings

Demonstrates the use of Josephson junctions for broadband impedance matching.

Shows potential to increase axion search scan rates.

Addresses fundamental gain-bandwidth trade-offs in detector design.

Abstract

The nonlinear inductance of the Josephson junction has enabled the development of a wide range of continuous-variable amplifiers and qubit-based devices with unprecedented sensitivity. We present an alternative use of the Josephson junction in the context of broadband impedance matching. The idea poses a potential solution to a longstanding problem in the field of high energy particle physics. The axion, a compelling candidate for the dark matter, converts to a weak electromagnetic signal at an as-yet unknown frequency. As such, the ideal axion detector does not compromise bandwidth for sensitivity, a trade-off intrinsic to all linear, time-invariant and passive circuits. We propose a circuit that uses a Josephson junction in an impedance matching network to overcome these gain-bandwidth constraints and increase the scan rate of axion searches. The Josephson junction can be biased to exhibit negative inductance capable of canceling geometric inductance similar to a capacitor but across a wider frequency range.