Understanding drive-induced state transitions in fluxonium: part 2/2

Fluxonium is a promising qubit platform with long coherence times. For reaching high fidelity, fast, and scalable two-qubit gates or for using them as couplers between other systems, these non-linear devices often need to be strongly driven over a selection of frequencies. It is therefore crucial to understand the impact on the qubit computational subspace by such a drive at various frequencies, not only near the resonator frequency as discussed in the last part of the talk.

In this presentation, we experimentally study the effects of strong drives on fluxonium qubits. We use Floquet calculations and multilevel branch analysis to model and understand the observed features. In part 2 of this two-part talk, we will focus on undesired state transitions during strong drives at frequencies away from the resonator frequency.