We reanalyse theoretical considerations and experimental data, in an attempt to decide whether there is another scale in the fractional quantum Hall effect problem, in addition to the magnetic scale defined by the magnetic length a c or the cyclotron energy ¯ hω c. We then discuss possible implications of a new scale on the formulation of a theoretical model of the fractional quantum Hall effect.

It is argued that fractional quantum Hall effect wavefunctions can be interpreted as conformal blocks of two-dimensional conformal field theory. Fractional statistics can be extended to nonabelian statistics and examples can be constructed from conformal field theory. The Pfaffian state is related to the 2D Ising model and possesses fractionally charged excitations which are predicted to obey n...

The trial wave function of the fractional quantum Hall effect (FQHE) on a disk at filling ν = 1/m with m an old integer is given by the famous Laughlin wave function [1]. Laughlin wave function had been constructed on a spheric or a toric surface later in refs. [2, 3]. When ν 6= 1/m, there are several proposals for constructing the trial wave function, notably Halperin’s hierarchical wave funct...

The diagonal conductivity usr was measured in the Corbino geometry in both integer and fractional quantum Hall effect (QHE). We find that peak values of g=.+ are approximately equal for transitions in a wide range of integer filling factors 3 < v < 16, as expected in scaling theories of QHE. This fact allows us to compare peak values in the integer and fractional regimes within the framework of...

The " exotic " particle model with non-commuting position coordinates , associated with the two-parameter central extension of the planar Galilei group, can be used to derive the ground states of the Fractional Quantum Hall Effect. The relation to other NC models is discussed. Anomalous coupling is presented. Similar equations arise for a semiclassical Bloch electron, used to explain the anoma-...

A simple one-dimensional model is proposed, in which N spinless repulsively interacting fermions occupy M>N degenerate states. It is argued that the energy spectrum and the wavefunctions of this system strongly resemble the spectrum and wavefunctions of 2D electrons in the lowest Landau level (the problem of the Fractional Quantum Hall Effect). In particular, Laughlin-type wavefunctions describ...

Division of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, USA Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA Department of Physics and Astronomy, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA Bell Labs, ...