Comments on "Competition Between Fractional Quantum Hall Liquid ...", by G. Gervais, L. W. Engel, H. L. Stormer, D. C. Tsui, et al (cond-mat/0402169)

TL;DR

This paper critiques the interpretation of certain fractional quantum Hall effect data, arguing that the formation of composite fermions as claimed in previous work is not supported by the experimental evidence.

Contribution

It provides a critical analysis showing that the experimental data do not support the flux attachment interpretation of composite fermions in the quantum Hall effect.

Findings

Fractions 5/3, 8/5, 11/7, 14/9, 17/11 fit the flux attachment formula.

Fractions 4/11, 7/11, 12/7, 13/8, 15/11 do not fit the formula.

The data do not support the formation of composite fermions as previously claimed.

Abstract

The quantum Hall effect in ultra-high mobility GaAs/AlGaAs has been measured and plateaus are found at many different fractions. The resistivity is quantized as \rho =h/ie^2 where i exhibits many different values. The fractions 5/3, 8/5, 11/7, 14/9, 17/11 fit the formula, i=3p\pm 2/(2p \pm 1) and it is claimed that 2p flux quanta are attached to the electron. The fractions 4/11, 7/11, 12/7, 13/8 and 15/11 do not fit the expression for i, even then the authors insist that flux quanta are attached to the electron and hence composite fermions (CF) are formed. We report that the interpretation of the experimental data in terms of CF is incorrect.