Edge state tunneling in a point contact at filling fraction $\nu$=5/2

We investigate low temperature transport properties of quantum point contacts (QPCs) fabricated in a GaAs/AlGaAs 2-dimensional electron gas (2-DEG) with mobility 2000 m$^{2}$/Vs in a perpendicular magnetic field. The 2-DEG exhibits fractional quantum Hall effect, including a well-quantized plateau at $\nu$=5/2. We study the temperature and DC current bias dependence of the transport through the QPC at $\nu$=5/2 while preserving the same filling number in both the QPC and the bulk of the sample. We compare our results to theoretical predictions for quasi-particle tunneling in the weak coupling regime, and extract the quasi-particle charge and the strength of the Coulomb interaction, as reflected by the Luttinger liquid parameter $g$. This work was partially supported by ARO (W911NF-05-1-0062), by the NSEC program of NSF (PHY-0117795), by NSF (DMR-0353209) at MIT and by Project Q of Microsoft Corporation at Harvard University.