Pinning modes and interlayer correlation in high magnetic field bilayer   Wigner solids
  We report studies of pinning mode resonances in the low total Landau filling (\nu) Wigner solid of a series of bilayer hole samples with negligible interlayer tunneling, and with varying interlayer separation d. Comparison of states with equal layer densities (p,p) to single layer states (p,0) produced {in situ} by biasing, indicates that there is interlayer quantum correlation in the solid at small d. Also, the resonance frequency at small d is decreased just near \nu=1/2 and 2/3, indicating the importance in the solid of correlations related to those in the fractional quantum Hall effects. 
Zhihai Wang, Yong P. Chen, L. W. Engel, D. C. Tsui, E. Tutuc and M.   Shayegan