Fractional statistics in anyon collisions*

Two-dimensional systems can host exotic particles called anyons [1,2] whose quantum statistics are neither bosonic nor fermionic. For example, the elementary excitations of the fractional quantum Hall effect at filling factor ν = 1/m (where m is an odd integer) have been predicted to obey Abelian fractional statistics, with a phase phi associated with the exchange of two particles equal to π/m. However, despite numerous experimental attempts, clear signatures of fractional statistics have remained elusive. We experimentally demonstrate Abelian fractional statistics at filling factor ν = 1/3 by measuring the current correlations resulting from the collision between anyons at a beamsplitter [3]. By analyzing their dependence on the anyon current impinging on the splitter and comparing with recent theoretical models, we extract phi = π/3, in agreement with predictions [4].

[1] B. I. Halperin, Phys. Rev. Lett. 52, 1583–1586 (1984).
[2] D. Arovas et al., Phys. Rev. Lett. 53, 722–723 (1984).
[3] H. Bartolomei et al., Science 368, 173-177 (2020).
[4] B. Rosenow et al., Phys. Rev. Lett. 116, 156802 (2016).