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arXiv · 2303.04181

Improved microwave SQUID multiplexer readout using a kinetic-inductance traveling-wave parametric amplifier

M. Malnou·J. A. B. Mates·M. R. Vissers·L. R. Vale·D. R. Schmidt·D. A. Bennett·J. Gao·J. N. Ullom
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Abstract

We report on the use of a kinetic-inductance traveling-wave parametric amplifier (KITWPA) as the first amplifier in the readout chain of a microwave superconducting quantum interference device (SQUID) multiplexer (umux). This umux is designed to multiplex signals from arrays of low temperature detectors such as superconducting transition-edge sensor microcalorimeters. When modulated with a periodic flux-ramp to linearize the SQUID response, the flux noise improves, on average, from $1.6$ $\mu\Phi_0/\sqrt{\mathrm{Hz}}$ with the KITWPA off, to $0.77$ $\mu\Phi_0/\sqrt{\mathrm{Hz}}$ with the KITWPA on. When statically biasing the umux to the maximally flux-sensitive point, the flux noise drops from $0.45$ $\mu\Phi_0/\sqrt{\mathrm{Hz}}$ to $0.2$ $\mu\Phi_0/\sqrt{\mathrm{Hz}}$. We validate this new readout scheme by coupling a transition-edge sensor microcalorimeter to the umux and detecting background radiation. The combination of umux and KITWPA provides a variety of new capabilities including improved detector sensitivity and more efficient bandwidth utilization.

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M. Malnou, J. A. B. Mates, M. R. Vissers, L. R. Vale, D. R. Schmidt, D. A. Bennett, J. Gao, J. N. Ullom. 2023-03-07. Improved microwave SQUID multiplexer readout using a kinetic-inductance traveling-wave parametric amplifier. https://doi.org/10.1063/5.0149646

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