Topological acoustics in coupled nanocavity arrays

TL;DR

This paper proposes a practical implementation of the SSH topological model using coupled acoustic nanoresonators in the GHz-THz range, enabling tunable topological phases and direct experimental probing of edge states.

Contribution

It introduces a feasible nanoresonator-based platform for simulating topological phases with tunable parameters and methods for directly observing topological edge states.

Findings

Demonstration of tunable topological transition points

Construction of nanophononic edge and interface states

Proposed optical pump-probe technique for state detection

Abstract

The Su-Schrieffer-Heeger (SSH) model is likely the simplest one-dimensional concept to study non-trivial topological phases and topological excitations. Originally developed to explain the electric conductivity of polyacetylene, it has become a platform for the study of topological effects in electronics, photonics and ultra-cold atomic systems. Here, we propose an experimentally feasible implementation of the SSH model based on coupled one-dimensional acoustic nanoresonators working in the GHz-THz range. In this simulator it is possible to implement different signs in the nearest neighbor interaction terms, showing full tunability of all parameters in the SSH model. Based on this concept we construct topological transition points generating nanophononic edge and interface states and propose an easy scheme to experimentally probe their spatial complex amplitude distribution directly by well-established optical pump-probe techniques.