Magnifying Quantum Phase Fluctuations with Cooper-Pair Pairing
نویسندگان
چکیده
Remarkably, complex assemblies of superconducting wires, electrodes, and Josephson junctions are compactly described by a handful collective phase degrees freedom that behave like quantum particles in potential. The inductive wires contribute parabolic confinement, while the tunnel add cosinusoidal corrugation. Usually, ground state wavefunction is localized within single potential well -- is, fluctuations small although entering regime delocalization holds promise for metrology qubit protection. A direct route to loosen confinement let spread over multiple periods, but this requires circuit impedance vastly exceeding resistance constitutes an ongoing experimental challenge. Here we take complementary approach fabricate generalized element can be tuned situ between one- two-Cooper-pair tunneling, doubling frequency corrugation thereby magnifying number wells probed state. We measure tenfold suppression flux sensitivity first transition energy, implying twofold increase vacuum fluctuations.
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ژورنال
عنوان ژورنال: Physical Review X
سال: 2022
ISSN: ['2160-3308']
DOI: https://doi.org/10.1103/physrevx.12.021002