Polarization-Induced Topological Phase Transition In Zigzag Chains Composed Of Metal Nanoparticles

We theoretically study the topological optical properties in one-dimensional zigzag chains composed of metal nanoparticles. The topological phase transition in the system is realized by controlling the polarization of the external optical field, which is feasible in experiments in contrast with changing the structural parameters. The dipole responses of the system with different bond angles to the external field of arbitrary linear polarization are calculated. It is found that a wide domain of polarization angles is available for a given zigzag chain to observe the polarization-induced topological transition. Different topological phases in the system are checked, which further proves the effectiveness of polarization modulation. The system, an easily implemented platform to study phenomena in topological photonics, might have novel applications in nanoscale optical devices.