Dark state as a measurable state by a dispersive readout without a Purcell limit

Abstract:It is believed that the enhancement in qubit-resonator coupling allows a better dispersive readout but introduces greater Purcell loss. In this work, we propose that a dark mode in a coupled quantum system may violate this rule by introducing the ZZ interaction between the dark and a bright mode. The dark mode may exhibit an effective zero coupling strength, and zero Purcell loss with the resonator photons. Nevertheless, the dispersive shift is almost the same as the bright state, due to the higher order perturbation introduced by the higher excited states. Such a state demonstrates the measurability without a Purcell limit in circuit quantum electrodynamics.

arXiv:2608.29811 [quant-ph]

(or arXiv:2608.29811v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2608.29811 Focus to learn more arXiv-issued DOI via DataCite (pending registration)

arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.

Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.

Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.