Wigner crystallization about ν=3

Abstract

We measure a resonance in the frequency dependence of the real diagonal conductivity, Re[ σ xx ], near integer filling factor, ν=3. This resonance depends strongly on ν, with peak frequency f pk ≈1.7 GHz at ν=3.04 or 2.92 close to integer ν, but f pk ≈600 MHz at ν=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 ν=1 and 2. We interpret the resonance as due to a pinned Wigner crystal phase with density n ∗ about the ν=3 state.