Scientists have discovered a way to trap light inside magnetic materials. This breakthrough can have significant implications for various applications, such as magnetic lasers, magneto-optical memory devices, and quantum transduction. The experiment involved cooling a crystal to extremely low temperatures and placing it in a powerful magnetic field. By doing so, the scientists were able to confine light within the crystal, essentially bending it around magnetic field lines. This remarkable achievement opens up new possibilities in the field of photonics and quantum computing.
The researchers, led by Vinod M. Menon and his team at the City College of New York, focused on a layered magnet that contains excitons, which are quasiparticles with strong optical interactions. This material has the ability to trap light on its own, resulting in much stronger optical responses compared to typical magnets. When an external magnetic field is applied, the material's reflection of near-infrared light can change so dramatically that its color appears to change. This is known as a strong magneto-optic response.
Normally, light doesn't respond strongly to magnetism, which is why technologies that rely on magneto-optic effects often require sensitive optical detection methods. However, this new discovery opens up possibilities for creating magnetic lasers and reevaluating concepts of optically controlled magnetic memory. "Ordinarily, light does not respond so strongly to magnetism," said Menon. "This is why technological applications based on magneto-optic effects often require the implementation of sensitive optical detection schemes."
In their new article in Nature, Menon and his research team have presented their findings on a novel layered magnet. This magnet exhibits unique properties, as it is capable of hosting strongly bound excitons, which are quasiparticles with exceptionally strong optical interactions. One remarkable feature of this material is its ability to trap light autonomously, without the need for external assistance. Through their experiments, Menon and his team have demonstrated that this material displays optical responses to magnetic phenomena that are significantly more powerful than those observed in conventional magnets.
"Since the light bounces back and forth inside the magnet, interactions are genuinely enhanced," said Dr. Florian Dirnberger, the lead-author of the study. "To give an example, when we apply an external magnetic field the near-infrared reflection of light is altered so much, the material basically changes its color. That's a pretty strong magneto-optic response."