Paul Scherrer Institute PSI & ETH Zurich observe surprising quantum effect

Researchers at the Paul Scherrer Institute PSI and ETH Zurich have, for the first time, directly observed the optical Magnus effect, a phenomenon mirroring the way spin alters the trajectory of a ball in classical mechanics.

The team directed a tightly focused laser beam at a single ion, revealing that the point of maximum interaction shifted sideways, a finding with implications for controlling qubits in quantum computing. “The forces it generates could be used to couple qubits to one another, enabling more complex computations,” explains first author Philip Leindecker from PSI and ETH Zurich. The researchers report their findings in Physical Review Letters, detailing how accounting for this effect is crucial for precise qubit control.

Optical Magnus Effect Demonstrated with Trapped Calcium Ions This unexpected displacement, analogous to the spin imparted on a table tennis ball, has implications for the precision control of qubits in emerging quantum computers.

The team utilized an ion trap, employing electromagnetic fields to hold the electrically charged calcium atom nearly motionless, allowing for precise measurements of the light’s influence, ETH Zurich says. “Our ion acts like a tiny sensor that we can use to feel out the structure of the laser light,” explains first author Philip Leindecker from the PSI Center for Photon Science and the Department of Physics at ETH Zurich. The experiment successfully measured this shift with remarkable precision, detecting changes as small as a few hundred nanometres. Importantly, the magnitude of this shift proved dependent solely on the wavelength of the light, not the laser’s focusing intensity. Because laser light is used to manipulate qubits, accounting for the optical Magnus effect is crucial; unaddressed, the effect could introduce errors into quantum computations. Our ion acts like a tiny sensor that we can use to feel out the structure of the laser light. Philip Leindecker, PSI Center for Photon Science and the Department of Physics at ETH Zurich Laser Focus Shift Impacts Qubit Control The precision required for manipulating qubits hinges on a detailed understanding of laser-ion interactions, and recent work reveals a subtle but significant shift in that dynamic. This unexpected displacement arises from the altered electromagnetic field created when a laser beam is tightly focused. Rather than interacting strongest at the beam’s center, the ion experiences maximum force slightly to the side, a result that could introduce errors if not accounted for in qubit control systems. Laser light is routinely used to selectively change the state of qubits, and this effect could interfere with that precise manipulation. The findings, detailed in Physical Review Letters, underscore the need to incorporate the optical Magnus effect into models of qubit control. The forces it generates could be used to couple qubits to one another, enabling more complex computations. This wavelength dependency distinguishes the observed effect and has implications for quantum computing, where laser light manipulates qubits. The University of Amsterdam had previously predicted the optical Magnus effect theoretically, but this work provides the first experimental confirmation and detailed characterization. This makes it possible to measure a shift of just a few hundred nanometres. Source: https://www.psi.ch/en/news/media-releases/a-surprising-twist-in-the-quantum-world More like thisQuantum ComputingETH Zurich Enables Gates on 17,000 QubitsQuantum Research NewsQubit Surgery Boosts Quantum Error CorrectionArtificial IntelligenceIBM & ETH Zurich: 10-Year Quantum Algorithm InitiativeQuantum Research NewsETH Zurich reveals quantum behavior in nano-glass spheresStay currentSee today’s quantum computing news on Quantum Zeitgeist for the latest breakthroughs in qubits, hardware, algorithms, and industry deals. Tags: Dr. Donovan Dr. Donovan is a futurist and technology writer covering the quantum revolution. Where classical computers manipulate bits that are either on or off, quantum machines exploit superposition and entanglement to process information in ways that classical physics cannot. Dr. Donovan tracks the full quantum landscape: fault-tolerant computing, photonic and superconducting architectures, post-quantum cryptography, and the geopolitical race between nations and corporations to achieve quantum advantage. The decisions being made now, in research labs and government offices around the world, will determine who controls the most powerful computers ever built. Latest Posts by Dr. Donovan: Predicting spin-qubit candidates now includes phonon effects August 28, 2026 MIT study finds AI complicates the value of education August 28, 2026 Mevion accelerator powers Auburn’s space testing center August 28, 2026