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arXiv:2512.00790 · Physical Review Letters

Observation of individual vortex penetration in a coplanar superconducting resonator

Kirill Shulga, Shunsuke Nishimura, Pavel A. Volkov, Ryota Hasegawa, Miu Hirano, Takeyuki Tsuji, Takayuki Iwasaki, Mutsuko Hatano, Kento Sasaki, Kensuke Kobayashi

cond-mat.supr-conquant-phSubmitted Nov 30, 2025• Announced Dec 2, 2025• 1 citation• Revised Sep 11, 2026 (v3)
v1 · Nov 30, 2025v2 · Dec 6, 2025v3 · Sep 11, 2026
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Abstract

We demonstrate the microwave signatures of individual Abrikosov-vortex penetration events in superconducting microwave resonators. $λ/4$ resonators with a narrowed region near the grounded end acting as a vortex trap were fabricated and studied using microwave transmission spectroscopy at millikelvin temperatures. Sharp stepwise drops in resonance frequency are detected as a function of increasing external magnetic field, attributed to the entry of individual Abrikosov vortices in the narrow region. This interpretation is confirmed by NV center magnetometry revealing discrete vortex entry events on increasing field and the absence of such drops in a device with a wider narrowed region. Our results establish a method to investigate and manipulate the states of Abrikosov vortices with microwaves access and readout vortex configurations using magnetic-field sweeps and microwave drive.

Journal reference
Phys. Rev. Lett. 137, 116001 (2026)
DOI
10.1103/4zw3-hm6t
Comments
18 pages, 10 figures, Published in Physical Review Letters

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