Measurements of quasiparticle tunneling in the υ= 5/2 fractional quantum Hall state

International Center for Quantum Materials, Peking University, 100871, Beijing, P.R. China; Department of Physics, Massachusetts Institute of Technology, 02139, Cambridge, Massachusetts, USA; Department of Electrical Engineering, Princeton University, 08544, Princeton, New Jersey, USA
Physical review. B, Condensed matter (Impact Factor: 3.77). 04/2012; 85(16). DOI: 10.1103/PhysRevB.85.165321

ABSTRACT Some models of the 5/2 fractional quantum Hall state predict that the quasiparticles, which carry the charge, have non-Abelian statistics: exchange of two quasiparticles changes the wave function more dramatically than just the usual change of phase factor. Such non-Abelian statistics would make the system less sensitive to decoherence, making it a candidate for implementation of topological quantum computation. We measure quasiparticle tunneling as a function of temperature and dc bias between counterpropagating edge states. Fits to theory give e*, the quasiparticle effective charge, close to the expected value of e/4 and g, the strength of the interaction between quasiparticles, close to 3/8. Fits corresponding to the various proposed wave functions, along with qualitative features of the data, strongly favor the Abelian 331 state.

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