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arXiv · 1910.07978

A gate-tunable, field-compatible fluxonium

Marta Pita-Vidal·Arno Bargerbos·Chung-Kai Yang·David J. van Woerkom·Wolfgang Pfaff·Nadia Haider·Peter Krogstrup·Leo P. Kouwenhoven·Gijs de Lange·Angela Kou
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Abstract

Circuit quantum electrodynamics, where photons are coherently coupled to artificial atoms built with superconducting circuits, has enabled the investigation and control of macroscopic quantum-mechanical phenomena in superconductors. Recently, hybrid circuits incorporating semiconducting nanowires and other electrostatically-gateable elements have provided new insights into mesoscopic superconductivity. Extending the capabilities of hybrid flux-based circuits to work in magnetic fields would be especially useful both as a probe of spin-polarized Andreev bound states and as a possible platform for topological qubits. The fluxonium is particularly suitable as a readout circuit for topological qubits due to its unique persistent-current based eigenstates. In this Letter, we present a magnetic-field compatible hybrid fluxonium with an electrostatically-tuned semiconducting nanowire as its non-linear element. We operate the fluxonium in magnetic fields up to 1T and use it to observe the $φ_0$-Josephson effect. This combination of gate-tunability and field-compatibility opens avenues for the exploration and control of spin-polarized phenomena using superconducting circuits and enables the use of the fluxonium as a readout device for topological qubits.

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Marta Pita-Vidal, Arno Bargerbos, Chung-Kai Yang, David J. van Woerkom, Wolfgang Pfaff, Nadia Haider, Peter Krogstrup, Leo P. Kouwenhoven, Gijs de Lange, Angela Kou. 2020-10-01. A gate-tunable, field-compatible fluxonium. https://doi.org/10.1103/physrevapplied.14.064038

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