Scientists trap light inside a magnet – paving the way for technical innovations

Researchers have discovered that confining light in certain magnetic materials can greatly amplify their properties, providing potential innovations such as magnetic lasers and a new perspective on optically controlled magnetic memory.

A groundbreaking study by Vinod M Menon and his team at the City College of New York reveals that trapping light inside magnetic materials can greatly enhance their intrinsic properties. These increased photonic interactions in magnets pave the way for innovations in magnetic lasers, magneto-optical memory devices, and even in emerging quantum teleportation applications.

As detailed in their new article published August 16 in the journal natureMenon and his team investigated the properties of layered magnets hosting highly correlated excitons — quasiparticles with particularly strong photonic interactions. Because of that, matter is able to trap light — all on its own. As their experiments show, the optical responses of this material to magnetic phenomena are stronger than those of typical magnets.

Light trapped inside a magnetic crystal can strongly enhance its magneto-optical interactions. Credit: Rezlind Bushati

“Because the light bounces back and forth inside the magnet, the interactions are really enhanced,” said Dr. Florian Dernberger, lead author of the study. “To give an example, when we apply an external magnetic field, the reflectance of near-infrared light changes a lot, and the material basically changes its color. This is a very strong magneto-optical response.”

“Normally, light does not respond strongly to magnetism,” Menon said. “This is why technological applications based on magneto-optical effects often require the implementation of sensitive optical detection schemes.”

On how advances can benefit ordinary people, study co-author Jimin Kwan noted: “Technological applications of magnetic materials today are mostly associated with electromagnetic phenomena. Given these strong interactions between magnetism and light, we can now hope to one day create lasers.” magnetic and we may revisit old notions of optically controlled magnetic memory.”

Reference: “Magnetic Optics in Van der Waals Magnets Tuned by Self-Hybridized Polarities” by Florian Dernberger, Giamin Cowan, Rislind Bouchaty, Jeffrey M. Dederich, Matthias Florian, Julien Klein, Ksenia Musina, Zdenek Sofer, Xiaodong Xu and Akashdeep. Kamra, Francisco J. García-Vidal, Andrea Alù and Vinod M. Menon, Aug. 16, 2023, Available here. nature.
DOI: 10.1038/s41586-023-06275-2

Rislind Bushati, a graduate student in Menon’s group, also contributed to the experimental work.

The study, conducted in close collaboration with Andrea Alù and his group at the CUNY Center for Advanced Science Research, is the result of a major international collaboration. Experiments performed at CCNY and ASRC were supplemented with measurements taken in Washington University In the collection of Professor Xiaodong Xu by Dr. Jeffrey Diederich. Theoretical support was provided by Dr. Akashdeep Kamra and Professor Francisco J. Garcia Vidal of the Autonomous University of Madrid and Dr. Matias Florian of the University of Michigan. The materials were developed by Professors Zdenek Sofer and Kseniia Mosina at UCT Prague and the project was supported by Dr Julian Klein at Massachusetts Institute of Technology. Work at CCNY was supported by the US Air Force Office of Scientific Research, the National Science Foundation (NSF) – Materials Research Division, and the NSF CREST IDEALS Center, DarpaGerman Research Foundation.