Glass sphere entangled with light at room temperature, researchers report

A team led by Francesco Marin at the University of Florence entangled the motion of a tiny levitating glass sphere with light at room temperature, according to Phys.org, which reported on 7 October 2026 on a study published in the journal Science. The sphere measured 100 nanometers (one billionth of a meter) across.

The team held the sphere in a tightly focused laser beam called an optical tweezer, positioned between two facing mirrors inside a near-vacuum chamber, Phys.org reported. On its own, the light needed to create entanglement also induced unwanted oscillations in the sphere, eventually knocking it out of its trap. To address this, the researchers combined two lasers of slightly different colors: one cooled and steadied the sphere's back-and-forth motion, while the other entangled that movement with the light.

As the sphere oscillated, information about its motion became imprinted on the light leaving the mirrors, according to the report. By measuring this light over many hours, the team reconstructed the full pattern of connections between the sphere's motion and the light. Phys.org said the measured correlations crossed a mathematical threshold confirming entanglement, even with the surrounding lab at room temperature, and that the entanglement persisted in light traveling away from the mirrors.

Previous experiments created brief bursts of entanglement between photons — particles of light — and vibrating macroscopic particles, but only at temperatures close to absolute zero, according to Phys.org. The report said physicists have more recently recognized that tiny glass spheres levitated by light could offer a promising alternative, because they float almost completely isolated from their surroundings.

Phys.org reported that Marin's team now hopes to strengthen the entanglement through refined experimental techniques and to control it actively rather than only observe it. The report said this could eventually allow several levitated spheres to be entangled through a shared field of light, offering new ways to test quantum mechanics at larger scales and possibly how it interacts with gravity. It could also support quantum networks in which information passes between moving objects that store it and light that carries it over long distances, according to the report.