Princeton University

School of Engineering & Applied Science

Competing 5/2 Fractional Quantum Hall States in Confined Geometry

Professor Xi Lin, Peking University
Engineering Quadrangle, B327
Tuesday, October 18, 2016 - 1:30pm

Some theories predict that the filling factor 5/2 fractional quantum Hall state can exhibit non-Abelian statistics, which makes it a candidate for fault-tolerant topological quantum computation. While the non-Abelian Pfaffian state and its particle-hole conjugate, the anti-Pfaffian state, are the most plausible wave functions for the 5/2 state, there are a number of alternatives with either Abelian or non-Abelian statistics. Recent experiments suggest that the tunneling exponents are more consistent with an Abelian state rather than a non-Abelian state. Here we present edge-current-tunneling experiments in geometrically confined quantum point contacts, which indicate that Abelian and non-Abelian states may compete at filling factor 5/2.