RF Conductivity Study of Electron Correlations in the Small Filling-Factor Limit

摘要: We have determined the dynamical conductivity σ(k,ω) of 2D electrons in high mobility GaAs/AlGaAs heterostructures by measuring attenuation and velocity surface acoustic waves as a function magnetic field, temperature frequency. In small filling factor limit lowest Landau level we find broad resonance with sharp onset temperature. interpret this pinning mode Wigner glass rather than ω ∝ k 3/2 shear expected perfect crystal. This contributes to both real imaginary part conductivity, is centered at about 1 GHz From frequency get rough estimate ξ ≈ µm for correlation length crystal