Heikki Suominen

Multiplexed readout of ultrasensitive bolometers

  1. Priyank Singh,
  2. András Gunyhó,
  3. Heikki Suominen,
  4. Giacomo Catto,
  5. Florian Blanchet,
  6. Qi-Ming Chen,
  7. Arman Alizadeh,
  8. Aarne Keränen,
  9. Jian Ma,
  10. Timm Mörstedt,
  11. Wei Liu,
  12. and Mikko Möttonen
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 coarse. 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 \SI{150}{\mega\hertz} — \SI{200}{\mega\hertz}, which is well detuned from the heater frequencies of \SI{4.4}{\giga\hertz} — \SI{7.6}{\giga\hertz} 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.
arxiv pdf