Design, Fabrication and Characterization of Microwave Multiplexing SQUID Prototype

TL;DR

This paper presents the design, fabrication, and characterization of a 32-channel microwave SQUID multiplexer prototype, demonstrating its potential for large-scale cryogenic detector readouts.

Contribution

The study develops and tests a new microwave SQUID multiplexer prototype with 32 channels, advancing multiplexing technology for large-scale detector arrays.

Findings

Achieved a multiplexing ratio of 2000:1 within the readout bandwidth.

Measured an equivalent noise current of 154 pA/√Hz.

Successfully measured 8 channels of the prototype.

Abstract

The readout system with a high multiplexing ratio has become a bottleneck limiting the application of large-scale Transition Edge Sensor (TES) detector arrays. In recent years, the microwave superconducting quantum interference device (SQUID) multiplexer has emerged as a key technology for effectively reading large-scale cryogenic detector arrays. Currently, the microwave SQUID multiplexer is being adopted by an increasing number of experiments due to its capability of achieving a multiplexing ratio of 2000:1 within the readout bandwidth. In this study, we developed and fabricated a 32-channel microwave SQUID multiplexer prototype. And we measured 8 channels of the prototype. The measured equivalent noise current of the prototype reached 154 pA/$\sqrt{Hz}$.