Collective modes in the fluxonium qubit

G. Viola; G. Catelani

doi:10.1103/physrevb.92.224511

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arXiv · 1506.08599

Collective modes in the fluxonium qubit

G. Viola·G. Catelani

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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.

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G. Viola, G. Catelani. 2015-06-29. Collective modes in the fluxonium qubit. https://doi.org/10.1103/physrevb.92.224511

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