Fast universal control of a flux qubit via exponentially tunable wave-function overlap

التفاصيل البيبلوغرافية
العنوان: Fast universal control of a flux qubit via exponentially tunable wave-function overlap
المؤلفون: Krøjer, Svend, Dahl, Anders Enevold, Christensen, Kasper Sangild, Kjaergaard, Morten, Flensberg, Karsten
سنة النشر: 2023
المجموعة: Condensed Matter
Quantum Physics
مصطلحات موضوعية: Quantum Physics, Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: Fast, high fidelity control and readout of protected superconducting qubits are fundamentally challenging due to their inherent insensitivity. We propose a flux qubit variation which enjoys a tunable level of protection against relaxation to resolve this outstanding issue. Our qubit design, the double-shunted flux qubit (DSFQ), realizes a generic double-well potential through its three junction ring geometry. One of the junctions is tunable, making it possible to control the barrier height and thus the level of protection. We analyze single- and two-qubit gate operations that rely on lowering the barrier. We show that this is a viable method that results in high fidelity gates as the non-computational states are not occupied during operations. Further, we show how the effective coupling to a readout resonator can be controlled by adjusting the externally applied flux while the DSFQ is protected from decaying into the readout resonator. Finally, we also study a double-loop gradiometric version of the DSFQ which is exponentially insensitive to variations in the global magnetic field, even when the loop areas are non-identical.
Comment: 11 pages, 7 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2303.01102
رقم الأكسشن: edsarx.2303.01102
قاعدة البيانات: arXiv