Cryo-CMOS Control Modeling for Fluxonium Qubits

Scaling up to a full-scale multi-qubit processor adds complexity to the control signals input requirements which can be addressed by the use of specially designed cryogenic interface circuits. In this paper, we discuss the use of cryogenic classical electronics for control of a fluxonium artificial atom. In recent years, fluxonium has gained notoriety among the superconducting qubit community for exceptionally long coherence times and large anharmonicity - both highly desirable properties when designing the next generation of qubit systems. The feasibility of controlling a fluxonium based quantum processors with a compact control system ultimately enables a highly scalable system; however, the cryogenic environment poses very strict requirements on electronics. Many trade-offs arise in terms of noise, power consumption, and circuit complexity. Addressing these requires comprehensive simulations that account for the physics of fluxonium qubits and the potential impact of control circuits on their performance. This paper focuses on the models and specification derivation for qubit control and explores constraints in fluxonium-based system design. The models and specifications derived enable the design of optimal control circuits targeted for scalable fluxonium quantum processors.