Commensurate-incommensurate transition and associated collective modes in the stripe state of cuprates near 1/8 hole-doping

We analyze the anomalous behavior in hole-doped cuprates near 1/8 doping in terms of the commensurate-incommensurate transition of a stripe phase. Based on an effective Ginzburg-Landau theory appropriate for weak pinning, we calculate the commensurate-incommensurate transition point and the energies of the phason and amplitudon collective modes. Using experimentally available parameters, we estimate the phason gap (pinning frequency), the conductivity, and the contribution of the phason mode to the dielectric function.