Recently, ultrasensitive calorimeters have been proposed as a resource-efficient solution for multiplexed qubit readout in superconducting large-scale quantum processors. However, experiments demonstrating frequency multiplexing of these superconductor--normal--conductor--superconductor (SNS) sensors are are lacking in the literature. To this end, we present the design, fabrication, and operation of three SNS sensors with frequency-multiplexed input and probe circuits, all on a single chip. These devices have their probe frequencies in the range 150 MHz--200 MHz, which is well detuned from the heater frequencies of 4.4 GHz--7.6 GHz compatible with typical readout frequencies of superconducting qubits. Importantly, we show on-demand triggering of both individual and multiple low-noise SNS bolometers with very low cross talk. These experiments pave the way for multiplexed bolometric characterization and calorimetric readout of multiple qubits, a promising step in minimizing related resources such as the number of readout lines and microwave isolators in large-scale superconducting quantum computers.
@article{arxiv.2411.12782,
title = {Multiplexed readout of Superconductor--Normal-Conductor--Superconductor bolometers},
author = {Priyank Singh and András Gunyhó and Heikki Suominen and Giacomo Catto and Florian Blanchet and Qi-Ming Chen and Arman Alizadeh and Aarne Keränen and Jian Ma and Timm Mörstedt and Wei Liu and Mikko Möttonen},
journal= {arXiv preprint arXiv:2411.12782},
year = {2025}
}