The Floquet Fluxonium Molecule: Driving Down Dephasing in Coupled Superconducting Qubits

Abstract

High-coherence qubits, which can store and manipulate quantum states for long times with low error rates, are necessary building blocks for quantum computers. Here we propose a driven superconducting erasure qubit, the Floquet fluxonium molecule, which minimizes bit-flip rates through disjoint support of its qubit states and suppresses phase flips by a novel second-order insensitivity to flux-noise dephasing. We estimate the bit-flip, phase-flip, and erasure rates through numerical simulations, with predicted coherence times of approximately 50 ms in the computational subspace and erasure lifetimes of about 500 $\mu$s. We also present a protocol for performing high-fidelity single-qubit rotation gates via additional flux modulation, on timescales of roughly 500 ns, and propose a scheme for erasure detection and logical readout. Our results demonstrate the utility of drives for building new qubits that can outperform their static counterparts.

18 pages, 1 figure

References in corpus (9)

• Qubit-photon interactions in a cavity: Measurement induced dephasing and number splitting
• Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays
• Moving beyond the transmon: Noise-protected superconducting quantum circuits
• Circuit quantization in the presence of time-dependent external flux
• Erasure qubits: Overcoming the $T_1$ limit in superconducting circuits
• Dual-rail encoding with superconducting cavities
• High threshold codes for neutral atom qubits with biased erasure errors
• Demonstrating a long-coherence dual-rail erasure qubit using tunable transmons
• Boosting the Quantum State of a Cavity with Floquet Driving

Cited by in corpus (5)

• Frozonium: Freezing Anharmonicity in Floquet Superconducting Circuits
• Theory of quasiparticle generation by microwave drives in superconducting qubits
• Optimization of Floquet fluxonium qubits with commensurable two-tone drives
• Floquet-engineered fast SNAP gates in weakly coupled circuit-QED systems
• Proposal for erasure conversion in integer fluxonium qubits