A quantum computer made of trapped ions played the role of a tiny universe. In it, particles didn't just move; they wove into knots that change their properties when swapped. Such knots are called Fibonacci anyons: they aren't ordinary particles but rather vortices in the fabric of space.
Physicists wanted to see how this universe reaches thermal equilibrium, like a cup of coffee cooling to room temperature. To do this, they performed up to 47 sequential 'swaps' of the knots. Each swap is like a move in a complex game where the rules are set by a non-Abelian gauge theory — the kind that describes strong interactions inside atomic nuclei.
This approach opens the door to simulating realistic field theories on quantum computers. Instead of simplified one-dimensional models, we can now tackle two-dimensional and more complex ones: those where space already resembles ours.
as written by the authors arXiv:2601.13530
Nonequilibrium dynamics of quantum many-body systems is one of the main targets of quantum simulations. This focus - together with rapid advances in quantum-computing hardware - has driven increasing applications in high-energy physics, particularly in lattice gauge theories. However, most existing experimental demonstrations remain restricted to (1+1)-dimensional and/or abelian gauge theories, such as the Schwinger model and the toric code. It is essential to develop quantum simulations of nonabelian gauge theories in higher dimensions, addressing realistic problems in high-energy physics. To fill the gap, we demonstrate a quantum simulation of thermalization dynamics in a (2+1)-dimensional $$q$$-deformed $$\mathrm{SU}(2)_3$$ Yang-Mills theory using a trapped-ion quantum computer. By restricting the irreducible representations of the gauge fields to the integer-spin sector of $$\mathrm{SU}(2)_3$$, we obtain a simplified yet nontrivial model described by Fibonacci anyons, which preserves the essential nonabelian fusion structure of the gauge fields. We successfully simulate the real-time dynamics of this model using quantum circuits that explicitly implement $$F$$-moves. In our demonstrations, the quantum circuits execute up to 47 sequential $$F$$-moves. We identify idling errors as the dominant error source, which can be effectively mitigated using dynamical decoupling combined with a parallelized implementation of $$F$$-moves.
Fibonacci anyons are candidates for ultra-protected quantum computing: information is stored not in a particle, but in how their trajectories are braided.
The idea of particles that remember their history of swaps recalls the 'chrono-crystals' from Greg Egan's novel 'Schild's Ladder'.