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Physics

Long(er) Live the Fluxonium Qubit

Katherine Wright

Published Jun 29, 2023• 0 citations
Publisher

Abstract

Long(er) Live the Fluxonium QubitResearchers demonstrate a fluxonium qubit that retains its quantum information for 1.43 milliseconds, 10 times longer than the previous best lifetime for this system.
DOI
10.1103/physics.16.s92

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High-fidelity two-qubit gates have been demonstrated in systems of two fluxonium qubits; however, the realization of scalable quantum processors requires maintaining low error rates in substantially larger architectures. In this work, we analyze a system of four inductively coupled fluxonium qubits to determine the impact of spectator qubits on the performance of a \textsc{cnot} gate. Our results show that spectator-induced errors are strongly suppressed when the transition frequencies of the spectator qubits are sufficiently detuned from those of the active qubits. We identify favorable frequency configurations for the four-qubit chain that yield \textsc{cnot} gate errors below 10−410^{-4}10−4 for gate times shorter than 100 ns. Leveraging the locality of the nearest-neighbor coupling, we extrapolate our findings to longer fluxonium chains, suggesting a viable path toward scalable, low-error quantum information processing.