Los Chapitos.

Quantum computing.

1. The coat of arms of Italy’s aristocratic House of Borromeo contains an unsettling symbol: an arrangement of three interlocking rings that that cannot be pulled apart but doesn’t contain any linked pairs. That same three-way linkage is an unmistakable signature of one of the most coveted phenomena in quantum physics — and it has now been observed for the first time. Researchers have used a quantum computer to create virtual particles and move them around so that their paths formed a Borromean-ring pattern. The exotic particles are called non-Abelian anyons, or nonabelions for short, and their Borromean rings exist only as information inside the quantum computer. But their linking properties could help to make quantum computers less error-prone, or more ‘fault-tolerant’ — a key step to making them outperform even the best conventional computers. The results, revealed in a preprint on 9 May, were obtained on a machine at Quantinuum, a quantum-computing company in Broomfield, Colorado, that formed as a merger of the quantum computing unit of Honeywell and a start-up based in Cambridge, UK. “This is the credible path to fault-tolerant quantum computing,” says Tony Uttley, Quantinuum’s president and chief operating officer. Quanta magazine’s story on this is worth reading in full. (Sources: nature.com, quantinuum.com, quantamagazine.org, italics mine)