Multiplexed readout of superconductor-normal-conductor-superconductor bolometers

Recently, ultrasensitive calorimeters have emerged as a resource efficient solution for different applications, such as qubit readout, radiation sensors, etc. Multiplexing these detectors paves the path for a larger range of usage. However, experiments demonstrating frequency multiplexing of these superconductor-normal-conductor-superconductor (SNS) sensors 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 of 150-200 MHz, which is well detuned from the heater frequencies of 4.4-7.6 GHz compatible with typical readout frequencies used in different applications in microwave physics. Importantly, we show on-demand triggering of both individual and multiple low-noise SNS bolometers with minimal cross talk. These experiments pave the way for multiplexed bolometric characterization and calorimetric applications.