Collective modes in the fluxonium qubit

Abstract

Superconducting qubit designs vary in complexity from single- and few-junction systems, such as the transmon and flux qubits, to the many-junction fluxonium. Here we consider the question of wether the many degrees of freedom in the fluxonium circuit can limit the qubit coherence time. Such a limitation is in principle possible, due to the interactions between the low-energy, highly anharmonic qubit mode and the higher-energy, weakly anharmonic collective modes. We show that so long as the coupling of the collective modes with the external electromagnetic environment is sufficiently weaker than the qubit-environment coupling, the qubit dephasing induced by the collective modes does not significantly contribute to decoherence. Therefore, the increased complexity of the fluxonium qubit does not constitute by itself a major obstacle for its use in quantum computation architectures.

22 pages, 15 figures

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Cited by in corpus (14)

• The high-coherence fluxonium qubit
• Nanowire Superinductance Fluxonium Qubit
• Scalable High-Performance Fluxonium Quantum Processor
• Circuit design implementing longitudinal coupling: a scalable scheme for superconducting qubits
• Quantization of inductively-shunted superconducting circuits
• Inductively shunted transmon qubit with tunable transverse and longitudinal coupling
• Consistent Quantization of Nearly Singular Superconducting Circuits
• Right-sizing fluxonium against charge noise
• Dissipative protection of a GKP qubit in a high-impedance superconducting circuit driven by a microwave frequency comb
• Impact of Josephson junction array modes on fluxonium readout
• The superconducting circuit companion -- an introduction with worked examples
• Inhomogeneous Josephson junction chains for superinductance optimization
• Efficient modeling of superconducting quantum circuits with tensor networks
• Spectral signature of high-order photon processes enhanced by Cooper-pair pairing