Pinning and conductivity of two-dimensional charge-density waves in magnetic fields

The dynamical properties of the impurity pinning of phasons of the charge-density wave are investigated for two-dimensional electron systems in the presence of magnetic fields applied perpendicular to the system. The effect of magnetic fields is treated classically. It is found that there exists a finite size of domains if the impurity potential overwhelms the long-range part of mutual Coulomb interactions, and the magnetoconductivity tensor is evaluated in such cases. The cyclotron resonance is shown to be shifted and broadened. It is predicted that absorption of electromagnetic waves exists at the pinned-mode frequency though the oscillator strength will be smaller by a factor of ${\left({\omega }_c\tau \right)}^{-2\mathrm{}}$ than the cyclotron resonance if ${\omega }_c\tau \gg 1$, where ${\omega }_c$ and $\tau$ are the cyclotron frequency and the damping of the resonance, respectively.