Fig. 4: Phase of matter for the non-Abelian semimetal model.
From: Generalization of non-Hermitian spectral topology to hyperbolic lattices
a Phase diagram of the primitive cell (left) and the 2-supercell (right) in the complex m plane. Light orange and pink regions highlight the \({C}_{2}\ne 0\) phase and semimetal phase, while light cyan regions denote the trivial insulator phase. Blue and red squares represent the calculated phase transition points for the primitive cell and the 2-supercell, respectively. Errors are obtained by standard deviations of phase transition points from all samples, with these small values being covered by the data points. b \({\sigma }_{{{\rm{U}}}}^{(1)}\) (red) and \({\sigma }_{{{\rm{U}}}}^{(2)}\) (light red) when \(m=3+0.3i\). Filled circles show spectra from U(2) hyperbolic band theory [U(2)-HBT], and the dark solid line highlights their spectral boundary. c \({\sigma }_{{{\rm{U}}}}^{(1)}\) (red) and \({\sigma }_{{{\rm{U}}}}^{(4)}\) (light red) when \(m=5+0.5i\). The inset shows the lower branch of the spectra with the blue and green markers depicting the OBC spectra for two configurations of 1601 and 1142 sites.
