Topological Bloch–Zener oscillations in non-Hermitian graphene plasmonic waveguide arrays

Abstract

We investigate the topological Bloch–Zener oscillations for surface plasmon polaritons (SPPs) propagating in a Su–Schrieffer–Heeger plasmonic system, which composed of graphene dimer arrays with a potential gradient. The topological trivial and non-trivial band gaps are achieved to investigate the topological effect to plasmonic Bloch oscillations. The topological transition from trivial phase to non-trivial one through the exceptional point is realized by alternating the gain and loss in the graphene waveguide arrays. Zener tunneling of the SPP beam was observed in the parity-time (PT) symmetric region, which was prohibited in the PT-symmetric broken region. The numerical calculations demonstrated reasonable agreements with theoretical tight-binding model. Furthermore, a single dynamically stable zero-energy edge state was also found in these non-Hermitian plasmonic waveguide arrays.