JERUSALEM, Nov. 19 (Xinhua) -- Israeli researchers have found that light's magnetic component, long considered too weak to matter, actually plays a direct and important role in the Faraday effect phenomenon, the Hebrew University of Jerusalem said Wednesday in a statement.
The Faraday effect is a classical physics phenomenon in which the direction of light's electric field rotates as the light travels through a material placed inside a magnetic field.
Since its discovery in 1845 by Michael Faraday, scientists have generally believed that the rotation came entirely from the interaction between light's electric field and the electric charges inside the material.
The new study, published in Scientific Reports, suggested that light's magnetic field also interacts with the material, specifically with tiny magnetic spins inside it, contributing to the overall rotation of the light.
According to the researchers, this means that light influences matter not only electrically, as previously believed, but also magnetically.
To examine this mechanism, the researchers used advanced calculations based on the Landau-Lifshitz-Gilbert equation, a standard model describing how magnetic spins in a material change their direction over time.
Their results indicated that the magnetic field of light can generate a magnetic-like force inside the material, similar to the effect produced by a constant external magnet, according to the statement.
The researchers tested their model using terbium gallium garnet, a crystal commonly used in Faraday-effect experiments. They found that the magnetic component of light accounts for about 17 percent of the rotation at visible wavelengths and up to 70 percent in the infrared range.
According to the researchers, recognizing the magnetic influence of light could open up new directions in optics and magnetism, including applications in spintronics, optical data storage, and light-based control of magnetic states. The findings may also support the development of spin-based quantum computing technologies in the future. ■
