Observing anyonization of bosons in a quantum gas

Anyons1,2 are low-dimensional quasiparticles that obey fractional statistics, hence interpolating between bosons and fermions. In two dimensions, they exist as elementary excitations of fractional quantum Hall states3–5 and are believed to enable topological quantum computing6,7. One-dimensional anyons have been theoretically proposed, but their experimental realization has proven to be difficult. Here we observed emergent anyonic correlations in a one-dimensional strongly interacting quantum gas, resulting from the phenomenon of spin–charge separation8–10. A mobile impurity provides the necessary spin degree of freedom to engineer anyonic correlations in the charge sector and simultaneously acts as a probe to reveal these correlations. Starting with bosons, we tune the statistical phase to transmute bosons through anyons to fermions and observe an asymmetric momentum distribution11–14, a hallmark of anyonic correlations. Going beyond equilibrium conditions, we observed dynamical fermionization of the anyons15. This study opens the door to the exploration of non-equilibrium anyonic phenomena in a highly controllable setting15–17.