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High-Frequency Hopping conductivity of Disordered 2D-system in the IQHE Regime

I. L. Drichko·A. M. Diakonov·V. D. Kagan·I. Yu. Smirnov·A. I. Toropov
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Abstract

High frequency (hf) conductivity in the form $σ^{hf} = σ_1^{hf} - iσ_2^{hf}$ was obtained from the measurement of Surface Acoustic Waves (SAW) attenuation and velocity (f=30 MHz) in GaAs/AlGaAs heterostructures ($n=1.3-7\cdot 10^{11}cm^{-2}$). It has been shown that in the Integer Quantum Hall Effect (IQHE) regime for all the samples at magnetic fields corresponding to the middle of the Hall plateaus and T=1.5 K, $σ_1 / σ_2 =0.14 \pm 0.03$. The ratio $σ_1 / σ_2=0.15$ points the case when the high-frequency hopping conductivity mechanism (electronic transition between the localized states formed by "tight" pairs) is valid \cite{1}. Dependencies of $σ_1$ and $σ_2$ on temperature and magnetic field is analyzed width of the Landau band broadened by the impurity random potential is determined.

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I. L. Drichko, A. M. Diakonov, V. D. Kagan, I. Yu. Smirnov, A. I. Toropov. 1999-04-06. High-Frequency Hopping conductivity of Disordered 2D-system in the IQHE Regime. https://arxiv.org/abs/cond-mat/9904053

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