In the paper published in the journal Physical Review A as “Rapid Communication” (Phys. Rev. A 97, 011601(R) (2018), Tena Dubček, Bruno Klajn, Robert Pezer, Hrvoje Buljan and Dario Jukić have found out that the momentum distribution is not suitable observable for gas of anyons and proposed a time-of-flight measurement as a solution.

Anyones are 2D quantum particles that satisfy fractional statistics, interpolating between bosons and fermions. It is known that, for determining essential gas properties, the velocity distribution is relevant. In classical gas for example, Maxwell-Boltzman’s distribution couples the microscopic kinematics of particles in gas and gas temperature as a thermodynamic property. In quantum gases, a suitable momentum distribution has been observed, which has repeatedly played a key role in detecting new quantum states in ultracold gases: it was one of the signatures of Bose-Einstein’s condensation, ie the appearance of Fermi’s degeneration in confined atomic gas. However, Tena Dubček and colleagues have shown that the usual definition of momentum distribution needs to be reconsidered and changed for the gas of the anyons. They suggested that using the density of the anyons after free expansion as the distribution of quasi-momentum by performing time of flight measurements it is possible to identify anyone’s statistics. Lastly, it might be interesting in the context of quantum computing, because of the potential that (non-Abel) anyons might be a platform for quantum computers.