Speaker
Description
The Superconducting Quasiparticle-Amplifying Transmon (SQUAT) is a sensor architecture for meV (THz) detection based on a weakly charge-sensitive transmon qubit directly coupled to a transmission line. Energy depositions in the qubit capacitor generate quasiparticles that tunnel across the Josephson junction. Each tunnel changes the qubit parity and produces a measurable signal in CW transmission. SQUATs use junctions with lower-Tc than their capacitors to induce quasiparticle trapping near the junction and amplify the tunneling rate for a given energy deposition. Their enhanced sensitivity to quasiparticle events and intrinsic multiplexability make SQUATs a promising detector foundation for low-energy-threshold rare-event searches. In this talk, I will present the design and characterization of SQUAT-style detectors, including the newest generation of SQUATs with Ta-Al quasiparticle trapping and silicon target substrates. I will discuss background sources that influence the observed parity-switching rate as well as progress towards a position-dependent calibration using MEMS-based cryogenic optical beam steering.
Coauthors: Hannah Magoon (Stanford University / SLAC National Accelerator Laboratory), Taj Dyson (Stanford University / SLAC National Accelerator Laboratory), Grace Bratrud (Northwestern University), Alexander Droster (SLAC National Accelerator Laboratory), Riley Carpenter (Stanford University), Zachary Gillis (Stanford University), Jadyn Anczarski (Stanford University / SLAC National Accelerator Laboratory), Caleb Fink (Syracuse University), Aviv Simchony (Stanford University / SLAC National Accelerator Laboratory), Zoë Smith (Stanford University / SLAC National Accelerator Laboratory), Noah Kurinsky (Stanford University / SLAC National Accelerator Laboratory), Shannon Harvey (Stanford University / SLAC National Accelerator Laboratory), Chiara Salemi (UC Berkeley/LBNL), Betty Young (Santa Clara University), David Schuster (Stanford University / SLAC National Accelerator Laboratory)