Hanhee Paik, Antonio Mezzacapo, et al.
Physical Review Letters
We present a method for detecting electromagnetic (EM) modes that couple to a superconducting qubit in a circuit quantum electrodynamics architecture. Based on measurement-induced dephasing, this technique allows the measurement of modes that have a high quality factor (Q) and may be difficult to detect through standard transmission and reflection measurements at the device ports. In this scheme, the qubit itself acts as a sensitive phase meter, revealing modes that couple to it through measurements of its coherence time. Such modes are indistinguishable from EM modes that do not couple to the qubit using a vector network analyzer. Moreover, this technique provides useful characterization parameters including the quality factor and the coupling strength of the unwanted resonances. We demonstrate the method for detecting both high-Q coupling resonators in planar devices as well as spurious modes produced by a 3D cavity.
Hanhee Paik, Antonio Mezzacapo, et al.
Physical Review Letters
Seth Merkel, Antonio Córcoles, et al.
APS March Meeting 2020
Sarah Sheldon
APS March Meeting 2023
Sarah Sheldon, D.G. Cory
Physical Review A - AMO