Topological edge states in the Su-Schrieffer-Heeger model subject to balanced particle gain and loss Marcel Klett, Holger Cartarius, Dennis Dast, Jörg Main and Günter Wunner Eur. Phys. J. D, 72 12 (2018) 214 Published online: 11 December 2018 DOI: 10.1140/epjd/e2018-90502-3