Fractional statistics in anyon collisions

Two dimensional systems can host exotic quasiparticles, called anyons, which obey intermediate quantum statistics between fermions and bosons characterized by a phase φ varying between 0 and π [1,2]. As an example, in the fractional quantum Hall regime, obtained by applying a strong magnetic field perpendicular to a two-dimensional electron gas, elementary excitations carry a fractional charge [3,4] and obey fractional statistics [1,2] with an exchange phase φ=π/m (where m is an odd integer) for Laughlin states corresponding to a fractional filling υ=1/m of the first Landau level. 

    I will present how fractional statistics of anyons can be demonstrated in this system by implementing and studying anyon collisions at a beam-splitter [5,6]. The collisions are first studied in the low magnetic field regime, where the elementary excitations are electrons which obey the usual fermionic statistics. It leads to the observation of an antibunching effect in an electron collision: electrons systematically exit in two different arms of the beam-splitter. The observed result is completely different in the fractional quantum Hall regime at filling factor υ=1/3. Fractional statistics lead to a suppression of the antibunching effect and quasiparticles tend to bunch together in larger packets of charge in a single output of the splitter. This effect leads to the observation of negative correlations of the current fluctuations at the splitter outputs [6] in perfect agreement with recent theoretical predictions [5].