Hybrid Magnon Modes

Magnons readily interact with a wide variety of different excitations, including microwave and optical photons, phonons, and other magnons. Such hybrid magnon dynamic excitations have recently gained increased interest due to their potential impact on coherent information processing [1]. This in turn opens new pathways for hybrid quantum information systems [2–4]. Although quantum operations of magnons have been demonstrated in bulk magnets, the quantum property of propagating magnons in magnetic films remains a fundamental challenge in both physics and materials science and is key for building magnon-based quantum information devices.
I will discuss specific examples and strategies, where we developed fully integrated devices that form the essential building blocks for more complex integrated quantum systems. Towards this end, we demonstrated strong magnon-photon coupling in scalable coplanar devices using coplanar superconducting microwave photon resonators [5]. Based on this concept we have shown how two magnon resonators can be coupled over macroscopic distances, and using local time-resolved detection, we demonstrate coherent, Rabi-like, energy exchange between them [6]. Lastly, I will show how we demonstrated strongly nonreciprocal magnon transduction using nano-scale microwave antennae [7]. By matching the lateral dimensions of the antenna to the thickness of the ferromagnetic film, we can obtain isolation ratios in excess of 30 dB with a single transmission band in a broad frequency range. This provides a practical way for implementing high performance magnon isolation in magnetic thin-film devices for technological applications.
This work was supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division under Contract No. DE-SC0022060.

References:
[1] Y. Li, et al., J. Appl. Phys. 128, 130902 (2020).
[2] D. D. Awschalom, et al., IEEE Quantum Engin. 2, 5500836 (2021).
[3] Y. Li, et al., 2022 IEEE Intern. Electr. Dev. Meeting, 14.6.1 (2022).
[4] Z. Jiang, et al., “Appl. Phys. Lett. 123, 130501 (2023).
[5] Y. Li, et al., Phys. Rev. Lett. 123, 107701 (2019).
[6] M. Song, et al., arXiv:2309.04289.
[7] Y. Li, et al., Appl. Phys. Lett. 123, 022406 (2023).