Surface magnetoplasmons in semiconductors

This comment is intended to complete the picture of dispersion curves for surface polaritons for $n$-InSb with ${\overrightarrow{\mathrm{B}}}_0$ parallel to the surface and $\overrightarrow{\mathrm{k}}\parallel {\overrightarrow{\mathrm{B}}}_0$ as given by Wallis, Brion, Burstein, and Hartstein by including the dispersion curves for "degenerate" surface modes. The corresponding decay constants and electric field ratios have also been plotted.