Fig. 6.

Spectrum of the class A model on a semiinfinite cylinder as a function of the wave vector around the cylinder. Gray areas represent a continuum of bulk modes, whereas blue lines denote the chiral surface modes. Parameters chosen to obtain the figure are: $t=5\hspace{0.17em}{\text{Hz}}^2$, $\tilde{\mu }=16\hspace{0.17em}{\text{Hz}}^2$, and $\gamma =1\hspace{0.17em}{\text{Hz}}^2$.