A simple beam of light can turn a non-magnetic material into a temporary magnet.
Magnets are defined by the way they split the energy levels of electrons based on their spin. Researchers have now shown that circularly polarized light can create this same spin-splitting effect in materials that are not naturally magnetic. This process breaks a fundamental symmetry in physics that was previously thought to be unshakable. By using light instead of magnetism, engineers could create incredibly fast electronic switches that do not rely on heavy or expensive magnetic components. This discovery blurs the line between optical and magnetic materials for the next generation of computing. It means we can use lasers to control the digital logic of a computer at speeds that magnets cannot reach.
Light-Induced Even-Wave Spin Splittings in Nonmagnetic Centrosymmetric Systems with Spin-Orbit Coupling
arXiv · 2605.05316
Spin splitting underpins a vast range of spin-dependent phenomena. Traditionally, two primary mechanisms generate such splitting: relativistic spin-orbit coupling (SOC) and nonrelativistic magnetic exchange coupling (MEC). Governed by distinct symmetry constraints, they produce splittings of opposite parity -- odd for SOC and even for MEC -- a dichotomy that underpins the distinct spin physics of nonmagnetic and magnetic systems. In this work, we break this dichotomy by demonstrating the dynamic