Physicists discover a hidden “curveball” in quantum light

Researchers have experimentally demonstrated the optical Magnus effect for the first time, revealing that a tightly focused laser interacts most strongly with an atom slightly away from the beam’s center. The unexpected shift is similar to the physics that makes a spinning table tennis ball curve through the air. Because lasers are used to control qubits, the effect could create errors in quantum computers, but it might also provide a new way to couple qubits together.

Physicists discover a hidden “curveball” in quantum light. Physicists discover a hidden “curveball” in quantum light Science News from research organizations Physicists discover a hidden “curveball” in quantum light Date: September 13, 2026. That motion is caused by the Magnus effect, a familiar piece of physics that also influences the flight of larger balls in sports such as soccer.

Now, an international team working at the Paul Scherrer Institute PSI has observed a related effect at the atomic scale. For the first time, researchers have experimentally demonstrated the optical Magnus effect by focusing laser light on a single ion and measuring how the light interacts with it. Instead of causing an atom to follow a curved path, the effect shifts the location where the laser interacts most strongly with the ion.

That interaction point moves slightly sideways, a finding that could matter for quantum computers that use laser light to control qubits with extreme precision.