Deformed Fermi Surface Theory of Magneto-Acoustic Anomaly in Modulated Quantum Hall Systems Near $/nu=1/2$

Abstract

We introduce a new generic model of a deformed Composite Fermion-Fermi Surface (CF-FS) for the Fractional Quantum Hall Effect near $/nu=1/2$ in the presence of a periodic density modulation. Our model permits us to explain recent Surface Acoustic Wave observations of anisotropic anomalies [1,2] in sound velocity and attenuation- appearance of peaks and anisotropy - which originate from contributions to the conductivity tensor due to regions of the CF-FS which are flattened by the applied modulation. The calculated magnetic field and wave vector dependence of the CF conductivity,velocity shift and attenuation agree with experiments.

Revised manuscript (cond-mat/9807044) 23 September 1998; 10 pages

References in corpus (4)

• Towards a field theory of the fractional quantum Hall states
• Composite Fermions in Modulated Structures: Transport and Surface Acoustic Waves
• Velocity shift of surface acoustic waves due to interaction with composite fermions in a modulated structure
• Quasi-particle behavior of composite fermions in the half-filled Landau level