Simultaneous Operation of Co-fabricated Superconducting Qubits and Transition Edge Sensors

We present a system in which Transition Edge Sensors (TES) are co-fabricated in close proximity to transmon qubits on the same silicon substrate. The goal is to perform concurrent measurements of the TES devices and qubits, where the TES could serve a dual purpose: spectroscopic detection of cosmic background events and protection of qubits from those events via active energy removal.

In this talk, we discuss the technical challenges along this path. We review the fabrication processes and operational considerations necessary to maintain qubit coherence in the presence of TES integration. We then describe state-of-the-art protocols for simultaneous operation and calibration of TES devices and qubits. Finally, we discuss how the flavor of TES design and placement impacts the effectiveness of qubit protection.