Exceptional horns in $n$-root graphene and Lieb photonic ring lattices (opens in new tab)

Author(s): A. M. Marques, D. Viedma, V. Ahufinger, and R. G. DiasThe authors present here nth‑root versions of graphene and the Lieb lattice, built from unidirectional coupling loops. Dirac points turn into exceptional horns featuring sublinear |q|1/n scaling, and Landau levels exhibit ϕ1/(2n) flux dependence. Extra zero‑energy flat bands from sublattice imbalance further enrich the exceptional topology. A realistic photonic ring design using tailored gain and loss demonstrates how these mode...