The importance of edge states in the quantum Hall regime of the organic conductor

Abstract

We report measurements of the longitudinal magnetoresistance and magnetization of in pulsed magnetic fields of up to 50 T and temperatures down to 400 mK, using samples of different purity. Below 2 K the amplitude of the Shubnikov - de Haas oscillations in is found to decrease dramatically with falling temperature. This effect is shown to coincide with quasipersistent eddy current resonances in the magnetization, which are a signature of the quantum Hall effect. Evidence is provided for the existence of a novel interplane conduction mechanism involving highly metallic edge states with supressed scattering at the surface of the sample (a so-called `chiral Fermi liquid'), operational when the chemical potential is between Landau levels in the bulk of the material.