Simultaneous photonic and phononic topological pseudospin-dependent edge states in phoxonic crystals

School of Physics and Materials Science, Nanchang University - Nanchang 330031, China

^(a) 578689728@qq.com (corresponding author)

Received: 29 November 2021
Accepted: 8 April 2022

Abstract

The topological pseudospin-dependent edge states for sound and light are achieved simultaneously in phoxonic crystals (PxCs). By studying the topological phase transition mechanisms, we find that photonic bands can be inverted by changing the distance from the center of rods to the center of the unit cell, and phononic bands can be inverted by modifying the rotation angle of rods. Based on different adjustment schemes for light and sound, band inversions of both photonic and phononic modes are realized by simultaneously deforming the lattice and rotating the rods. Dual topological pseudospin-dependent edge states thus can be observed at the domain wall interfaces between two PxCs with distinct topological phases. The pseudospin-dependent one-way propagations and the topologically robust propagations against three types of defects for both light and sound are further numerically demonstrated. The proposed PxCs provide a platform for designing topologically integrated management of photons and phonons.