Universal Gates from Braiding and Fusing Anyons on Quantum Hardware
A quantum computer requires the ability to store and manipulate information globally to protect against local noise. Topologically ordered phases offer two routes: encoding information in the ground-state subspace or in anyonic excitations. The toric code exemplifies the first approach but does not intrinsically support a universal gate set. The latter—topological quantum computation—implements gates by braiding non-Abelian anyons around each other. However, the simplest non-Abelian generalizations of the toric code cannot achieve universality by braiding alone.
In a new article in Nature, a team of scientists from Harvard, Quantinuum, University of Chicago, and Stony Brook University demonstrated that anyon fusion, used as a computational primitive, renders these minimally non-Abelian topologically ordered states universal. They prepared a 54-qubit ground state of the quantum double of S3, the smallest non-Abelian group, on the H2 processor of Quantinuum and encoded logical information in the global fusion space of non-Abelian anyons. By combining braiding with fusion, they realized a universal topological gate set and read-out, which they demonstrated by topologically preparing a magic state and thus showing that the S3 topologically ordered state is scalably preparable, yet rich enough to support a universal gate set. More broadly, this work opens up new pathways for harnessing the intrinsic properties of quantum matter to manipulate quantum information.
Read the article: Lo, C.F.B., Lyons, A., Gresh, D. et al., "Universal gates from braiding and fusing anyons on quantum hardware," Nature 655, 591–597 (2026). https://doi.org/10.1038/s41586-026-10709-y
Also see "Braided, exotic particles could build reliable, universal quantum computers," by Sarah C.P. Williams (U Chicago) on phys.org.