Gatemonium: A Voltage-Tunable Fluxonium

First experimental demonstration of gatemonium, a voltage-tunable fluxonium built on an all-superconductor-semiconductor Al/InAs platform. The manuscript first appeared as a 2024 preprint and was published in PRX Quantum in 2025.

Key Results

• Device A used a 600-junction planar Al/InAs array and Device B used 400 junctions.
• Gate-dependent spectroscopy accessed light, intermediate, and heavy fluxonium regimes and required a nonsinusoidal weak-link current-phase relation for the best fits.
• Device B showed plasmon-mode Rabi oscillations, a Rabi-envelope decay of $102\pm 24$ ns, and $T_1=78\pm 4$ ns; the inferred $Q_L\sim 630$ indicated dominant inductive loss.

Links

• Journal: PRX Quantum 6, 010326 (2025)
• arXiv: 2406.09002

Zoo Links

• gatemonium
• gatemon
• fluxonium