Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
We analyze chiral topological edge modes in a non-Hermitian variant of the 2D Dirac equation. Such modes appear at interfaces between media with different "masses" and/or signs of the "non-Hermitian charge." The existence of these edge modes is intimately related to exceptional points of the bulk Hamiltonians, i.e., degeneracies in …