## ARTICLES Fractional quantum Hall effect in a quantum point contact at filling fraction 5/2 (2007)

Citations: | 5 - 0 self |

### BibTeX

@MISC{Miller07articlesfractional,

author = {Jeffrey B. Miller and Iuliana P. Radu and Dominik M. Zumbühl and Eli M. Levenson-falk and Marc A. Kastner and Charles M. Marcus and Loren N. Pfeiffer and Ken and W. West},

title = {ARTICLES Fractional quantum Hall effect in a quantum point contact at filling fraction 5/2},

year = {2007}

}

### OpenURL

### Abstract

Recent theories suggest that the quasiparticles that populate certain quantum Hall states should exhibit exotic braiding statistics that could be used to build topological quantum gates. Confined systems that support such states at a filling fraction ν = 5/2 are of particular interest for testing these predictions. Here, we report transport measurements of just such a system, which consists of a quantum point contact (QPC) in a two-dimensional GaAs/AlGaAs electron gas that itself exhibits a well-developed fractional quantum Hall effect at a bulk filling fraction ν bulk = 5/2. We observe plateau-like features at an effective filling fraction of ν QPC = 5/2 for lithographic contact widths of 1.2 µm and 0.8 µm, but not 0.5 µm. Transport near ν QPC = 5/2 in the QPCs is consistent with a picture of chiral Luttinger-liquid edge states with inter-edge tunnelling, suggesting that an incompressible state at ν QPC = 5/2 forms in this confined geometry. The discovery 1 of a fractional quantum Hall effect (FQHE) at the even-denominator filling fraction ν = 5/2 has sparked a series of experimental 2–6 and theoretical 7–9 studies, leading to a prevailing interpretation of the 5/2 state as comprising paired fermions condensed into a Bardeen–Cooper–Schrieffer-like state 10–13. Within this picture, excitations of the 5/2 ground state possess non-abelian statistics 14–16 and associated topological properties. The possibility