Researchers Observe the Optical Magnus Effect

(CONNECT) An international research team from the Paul Scherrer Institute (PSI) in Villigen, the Swiss Federal Institute of Technology Zurich (ETH), and the The University of Amsterdam has succeeded for the first time in experimentally demonstrating an optical Magnus effect. Researchers in Amsterdam had calculated this theoretically years ago. According to a press release, the researchers directed a highly focused laser beam at a single calcium ion. Observations of the optical interactions revealed that the strongest effects did not occur at the center—where the laser beam is most intensely focused—but slightly to the side of it. They found that this was caused by a significant change in the spatial structure of the electromagnetic field surrounding the laser beam.

This observed effect is called the optical Magnus effect, just like its counterpart in classical mechanics. There, a rotating cylinder is deflected at right angles to its direction of motion in a vortex-free flow. In sports, this phenomenon is familiar from topspin on table tennis balls or spin on soccer balls.

In this experiment, the researchers demonstrated that the central effect of the laser beam was strongest to the side of the calcium ion. In quantum computers, such a shift could lead to a loss of control over qubits that are intended to be selectively manipulated using laser light. However, taking this effect into account can also present an opportunity. “The forces generated in this process could be used to couple qubits with one another, thereby enabling more complex calculations,” Philip Leindecker of PSI’s Center for Photon Research is quoted as saying in the press release.

In the experiment, they used a calcium ion that was held in place by electromagnetic fields. When the focused laser beam was directed at the sample, displacements of several hundred nanometers were measured. When the wavelength of the beam changed, the effect was further amplified or attenuated.

The study was published in the journal*Physical Review Letters*. ce/ww