Theory of Magneto--Acoustic Transport in Modulated Quantum Hall Systems Near $\nu =1/2$

Abstract

Motivated by the experimental results of Willett et al [Phys.Rev. Lett., {\bf 78}, 4478 (1997)] we develop a magneto-transport theory for the response of a two dimensional electron gas (2DEG) in the Fractional Quantum Hall Regime near Landau level filling factor $\nu =1/2$ to the surface acoustic wave (SAW) in the presence of an added periodic density modulation. We assume there exists a Composite Fermion Fermi Surface (CF-FS) at $\nu =1/2$, and we show that the deformation of the (CF-FS) due to the density modulation can be at the origin of the observed transport anomalies for the experimental conditions. Our analysis is carried out particularly for the non-local case which corresponds to the SAW experiments. We introduce a new model of a deformed CF-FS. The model permits us to explain anomalous features of the response of the modulated 2DEG to the SAW near $\nu =1/2:$ namely the nonlinear wave vector dependence of the electron conductivity, the appearance of peaks in the SAW velocity shift and attenuation and the anisotropy of the effect, all of which originate from contributions to the conductivity tensor due to the regions of the CF-FS which are flattened by the applied modulation.

13 pages, 4 figures, the published version

References in corpus (6)

• Towards a field theory of the fractional quantum Hall states
• Quantum Group and Magnetic Translations. Bethe-Ansatz Solution for Azbel-Hofstadter Problem
• Magnetoresistance of a two-dimensional electron gas with spatially periodic lateral modulations: Exact consequences of Boltzmann's equation
• 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

Cited by in corpus (5)

• Local Geometry of the Fermi Surface and Magnetoacoustic Responce of Two-Dimensional Electron Systems in Strong Magnetic Fields
• Nonlinear absorption of surface acoustic waves by composite fermions
• On the Theory of a New Maximum Observed in dc Transport in Modulated Quantum Hall Systems Near ν=1/2
• Local Geometry of the Fermi Surface and Quantum Oscillations in the Linear Response of Metals
• Fermi-liquid effects in the transresistivity in quantum Hall double layers near $\nu =1/2$