Terahertz cavity magnon polaritons

T. Elijah Kritzell; Andrey Baydin; Fuyang Tay; Rodolfo Rodriguez; Hiroyuki Nojiri; Henry O. Everitt; Igor Barsukov; Junichiro Kono

doi:10.1002/adom.202302270

arXiv · 2308.10159

Terahertz cavity magnon polaritons

T. Elijah Kritzell·Andrey Baydin·Fuyang Tay·Rodolfo Rodriguez·Hiroyuki Nojiri·Henry O. Everitt·Igor Barsukov·Junichiro Kono

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Abstract

Hybrid light-matter coupled states, or polaritons, in magnetic materials have attracted significant attention due to their potential for enabling novel applications in spintronics and quantum information processing. However, most studies to date have been carried out for ferromagnetic materials with magnon excitations at gigahertz frequencies. Here, we have investigated strong resonant photon-magnon coupling at frequencies above 1 terahertz for the first time in a prototypical room-temperature antiferromagnetic insulator, NiO, inside a Fabry-Pérot cavity. The cavity was formed by the crystal itself when it was thinned down to an optimized thickness. By using terahertz time-domain spectroscopy in high magnetic fields up to 25 T, we swept the magnon frequency through Fabry-Pérot cavity modes and observed photon-magnon anticrossing behavior, demonstrating clear vacuum Rabi splittings exceeding the polariton linewidths. These results show that NiO is a promising platform for exploring antiferromagnetic spintronics and cavity magnonics in the terahertz frequency range.

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T. Elijah Kritzell, Andrey Baydin, Fuyang Tay, Rodolfo Rodriguez, Hiroyuki Nojiri, Henry O. Everitt, Igor Barsukov, Junichiro Kono. 2023-08-20. Terahertz cavity magnon polaritons. https://doi.org/10.1002/adom.202302270

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