Scientists Have Uncovered Light's Secret Magnetic Behaviors

In 1845, Michael Faraday first demonstrated the relationship between light and electromagnetism through what is now known as the Faraday Effect. Recently, a groundbreaking study has revealed that lights magnetic component has a much stronger influence on matter than previously understood, affecting up to 17% of atomic spin in the visible spectrum and as much as 75% in the infrared range.

This discovery opens exciting possibilities for scientists to control atomic spins in ways that could revolutionize storage technologies and sensor development.

Michael Faraday, a self-taught scientist from humble beginnings, became one of the most influential figures in the study of electromagnetism. He was a protg of British chemist Humphrey Davy and made foundational discoveries, including electromagnetic induction and the Faraday Effect, which describes the interaction between light and magnetism.

Faradays original experiment involved passing light through polarizers under the influence of electromagnets. He observed a faint flicker of light, revealing that electromagnetism can subtly affect the electric field of light.

Nearly two centuries later, physicists Benjamin Assouline and Amir Capua of the Hebrew University of Jerusalem have shown that light also exerts a magnetic influence on atomic spinsa phenomenon once thought negligible. The static magnetic field twists the light, and the light, in turn, reveals the magnetic properties of the material, Capua explained. The magnetic component of light is surprisingly active in this process.

Using the Landau-Lifshitz-Gilbert equation, the researchers demonstrated that light can generate a magnetic torque comparable to that of a static magnetic field. Experiments with Terbium Gallium Garnet (TGG), a material traditionally used to explore the Faraday Effect, revealed that the magnetic component of light accounts for 17% of atomic spin rotation in the visible spectrum and rises to 75% in the infrared.

Assouline emphasized, Our findings show that light communicates with matter not only via its electric field but also through its magnetic field, which has been largely ignored until now. Igor Rozhansky, a physicist at the University of Manchester, noted that this re-evaluation of lights magnetic influence could offer new methods to manipulate atomic spins, potentially enabling a new generation of spin-based sensors and memory devices.

Faradays pioneering work laid the groundwork for James Clerk Maxwells equations, which underpin modern technology. Yet, even after 180 years, light continues to reveal unexpected and remarkable properties that could reshape our understanding of physics and material science.

Author: Lucas Grant