Toward the First Implementation of Ctrl-VQE Pulses on Fluxonium Qubits

We present progress toward the first hardware-level realization of the control-variational quantum eigensolver (ctrl-VQE) on a two-fluxonium device with inductive coupling. The ctrl-VQE framework replaces discrete gate decompositions with shaped control fields that variationally steer the system toward the ground state of a target Hamiltonian [1]. Our platform consists of two inductively coupled fluxonium qubits whose low-energy manifold behaves closely to the case of two transversely coupled spin-1/2 systems [2]. This coupling topology has also demonstrated remarkable temporal stability—the fidelity remains above 99.9% for 24 days without any recalibration between randomized benchmarking measurements [3]—highlighting its suitability for long-duration variational protocols. We outline the device architecture, pulse-optimization workflow, and feedback-based energy-minimization loop used to implement ctrl-VQE at the waveform level. This effort establishes a foundation for hardware-efficient, fully analog approaches to quantum simulation and control using fluxonium-based superconducting circuits.