Year: 2026
Type: article
Abstract: Protecting superconducting qubits from low-frequency noise by operating them on dynamical sweet-spot manifolds has proven to be a promising setup, theoretically as well as experimentally . These dynamical sweet spots are induced by an externally applied Floquet drive, and various drive forms have been studied in different types of qubits. In this work we study the effects of using two-tone drives on the applied magnetic flux of the form $ϕ_{ac}(t)=ϕ_m\cos(mω_\mathrm{d} t)+ϕ_n\cos(nω_\mathrm{d} t+φ)$, where $m,n \in \mathbb{N}_{>0}$, on the coherence times of fluxonium qubits. The optimal drive parameters are found through analysis using perturbation theory and numerical calculations. We show that this type of drive allows for more tunability of the quasi-energy spectrum, creating higher and wider peaks of the dephasing time without affecting the relaxation times too strongly. Further we show that the second commensurable drive tone can be used to implement an improved phase gate compared to implementations with a single tone, supported by Monte Carlo simulations.
DOI: 10.1103/qcym-tqk8
Authors: Joachim Lauwens, Kristof Moors, Bart Sorée
Institutions: KU Leuven, IMEC, University of Antwerp
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4417097551