Realization of a Laughlin quasiparticle interferometer: Observation of fractional statistics
Abstract
In two dimensions, the laws of physics permit the existence of anyons, particles with fractional statistics which are neither Fermi nor Bose. That is, upon exchange of two such particles, the quantum state of a system acquires a phase which is neither 0 nor π , but can be any value. The elementary excitations (Laughlin quasiparticles) of a fractional quantum Hall fluid have a fractional electric charge and are expected to obey fractional statistics. In this paper we report experimental realization of a Laughlin quasiparticle interferometer, where quasiparticles of the 1/3 fluid execute a closed path around an island of the 2/5 fluid and thus acquire statistical phase. Interference fringes are observed as conductance oscillations as a function of magnetic flux, similar to the AharonovBohm effect. We observe the interference shift by one fringe upon introduction of five magnetic flux quanta (5h/e) into the island. The corresponding 2e charge period is confirmed directly in calibrated gate experiments. These results constitute direct observation of fractional statistics of Laughlin quasiparticles.
 Publication:

Physical Review B
 Pub Date:
 August 2005
 DOI:
 10.1103/PhysRevB.72.075342
 arXiv:
 arXiv:condmat/0502406
 Bibcode:
 2005PhRvB..72g5342C
 Keywords:

 73.43.f;
 05.30.Pr;
 Quantum Hall effects;
 Fractional statistics systems;
 Condensed Matter  Mesoscopic Systems and Quantum Hall Effect;
 Condensed Matter  Statistical Mechanics;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 manuscript of the long version published in Phys. Rev. B