Fluxonium: an alternative qubit platform for high-fidelity operations

Abstract

Superconducting qubits provide a promising path toward building large-scale quantum computers. The simple and robust transmon qubit has been the leading platform, achieving multiple milestones. However, fault-tolerant quantum computing calls for qubit operations at error rates significantly lower than those exhibited in the state of the art. Consequently, alternative superconducting qubits with better error protection have attracted increasing interest. Among them, fluxonium is a particularly promising candidate, featuring large anharmonicity and long coherence times. Here, we engineer a fluxonium-based quantum processor that integrates high qubit-coherence, fast frequency-tunability, and individual-qubit addressability for reset, readout, and gates. With simple and fast gate schemes, we achieve an average single-qubit gate fidelity of 99.97% and a two-qubit gate fidelity of up to 99.72%. This performance is comparable to the highest values reported in the literature of superconducting circuits. Thus our work, for the first time within the realm of superconducting qubits, reveals an approach toward fault-tolerant quantum computing that is alternative and competitive to the transmon system.

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Cited by in corpus (62)

• High-Fidelity, Frequency-Flexible Two-Qubit Fluxonium Gates with a Transmon Coupler
• Noisy intermediate-scale quantum computers
• High fidelity two-qubit gates on fluxoniums using a tunable coupler
• Scalable High-Performance Fluxonium Quantum Processor
• Optimizing quantum gates towards the scale of logical qubits
• Error per single-qubit gate below $10^{-4}$ in a superconducting qubit
• Quantum Instruction Set Design for Performance
• Gralmonium: Granular Aluminum Nano-Junction Fluxonium Qubit
• Unimon qubit
• Fast high-fidelity gates for galvanically-coupled fluxonium qubits using strong flux modulation
• FPGA-based electronic system for the control and readout of superconducting quantum processors
• Native two-qubit gates in fixed-coupling, fixed-frequency transmons beyond cross-resonance interaction
• Multi-mode architectures for noise-resilient superconducting qubits
• Fast and Robust Geometric Two-Qubit Gates for Superconducting Qubits and beyond
• Coupler microwave-activated controlled phase gate on fluxonium qubits
• A superconducting qubit with noise-insensitive plasmon levels and decay-protected fluxon states
• Native approach to controlled-Z gates in inductively coupled fluxonium qubits
• CNOT gates for fluxonium qubits via selective darkening of transitions
• Efficient initialization of fluxonium qubits based on auxiliary energy levels
• Generalized Toffoli gate decomposition using ququints: Towards realizing Grover's algorithm with qudits
• High coherence fluxonium manufactured with a wafer-scale uniformity process
• Classical Chaos in Quantum Computers
• Cavity-mediated entanglement of parametrically driven spin qubits via sidebands
• Ensemble-learning error mitigation for variational quantum shallow-circuit classifiers
• Individually Addressed Entangling Gates in a Two-Dimensional Ion Crystal
• Fast Flux Entangling Gate for Fluxonium Circuits
• Gatemonium: A Voltage-Tunable Fluxonium
• One Gate Scheme to Rule Them All: Introducing a Complex Yet Reduced Instruction Set for Quantum Computing
• Mitigating Errors on Superconducting Quantum Processors through Fuzzy Clustering
• Microwave-activated gates between a fluxonium and a transmon qubit
• The effects of disorder in superconducting materials on qubit coherence
• Characterization of a Transmon Qubit in a 3D Cavity for Quantum Machine Learning and Photon Counting
• Subgap states in semiconductor-superconductor devices for quantum technologies: Andreev qubits and minimal Majorana chains
• Flux-pulse-assisted Readout of a Fluxonium Qubit
• Hybrid cat-transmon architecture for scalable, hardware-efficient quantum error correction
• Tunneling of fluxons via a Josephson resonant level
• Quantum circuit simulation of superchannels
• Single-Qubit Gates Beyond the Rotating-Wave Approximation for Strongly Anharmonic Low-Frequency Qubits
• Verifying the analogy between transversely coupled spin-1/2 systems and inductively-coupled fluxoniums
• Heisenberg-limited Bayesian phase estimation with low-depth digital quantum circuits
• Integrating Quantum Processor Device and Control Optimization in a Gradient-based Framework
• Pure kinetic inductance coupling for cQED with flux qubits
• Noise reduction via optimal control in a light-matter quantum system
• Leakage Benchmarking for Universal Gate Sets
• Detector of microwave photon pairs based on a Josephson photomultiplier
• Parity-protected superconducting qubit based on topological insulators
• SuperGrad: a differentiable simulator for superconducting processors
• Cross-resonance control of an oscillator with an auxiliary fluxonium qubit
• Viewing protected superconducting qubits through the lens of the cat qubit
• Operation of a high-frequency, phase-slip qubit
• Heavy-hole spin relaxation in quantum dots: Isotropic versus anisotropic effects
• Protecting entanglement witnesses with randomized measurements
• Non-demolition fluorescence readout and high-fidelity unconditional reset of a fluxonium qubit via dissipation engineering
• Simultaneous sweet-spot locking of gradiometric fluxonium qubits
• Flux-Trapping Fluxonium Qubit
• Kicked fluxonium with quantum strange attractor
• Hybrid superinductance with Al/InAs
• Review of Superconducting Qubit Devices and Their Large-Scale Integration
• A fluxonium qubit-based hybrid electromechanical system
• Scalable phonon-laser arrays with self-organized synchronization
• Exact amplitudes of parametric processes in driven Josephson circuits
• Floquet-engineered system-reservoir interaction in the transverse field Ising model