Wigner crystallization about v=3

We measure a resonance in the frequency dependence of the real diagonal conductivity, Re{[}sigma(xx)], near integer filling factor, nu = 3. This resonance depends strongly on nu, with peak frequency f(pk) approximate to 1.7 GHz at v = 3.04 or 2.92 close to integer nu, but f(pk) approximate to 600 MHz at nu = 3.19 or 2.82, the extremes of where the resonance is visible. The dependence of f(pk) upon n{*}, the density of electrons in the partially filled level, is discussed and compared with similar measurements by Chen et al. (Phys. Rev. Lett., 91, 016801) about nu = 1 and 2. We interpret the resonance as due to a pinned Wigner crystal phase with density n{*} about the nu = 3 state. (C) 2003 Elsevier B.V. All rights reserved.