On the nature of the Fractional Quantum Hall Effect ground state at low fillings

摘要

We propose that the fractional quantum Hall effect structures recently observed in a narrow low temperature window below filling 115 correspond to a charge density wave exhibiting a depinning transition and further gap blurring as the temperature is increased. The main qualitative difference between the usual Wigner crystal and this charge density wave state is that while the former is featureless as the filling of the first Landau level changes, the latter exhibits cusps in the energy at odd fillings, as required by the odd-denominator rule that characterizes the effect, thus making possible the quantum Hall features. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.