Multiple phononic corner modes in 2D buckled arsenene

The theoretical framework of topological states has recently been expanded to include phononic systems. This study focuses on investigating the presence of multiple phononic corner modes in the phonon dispersion curves of 2D buckled arsenene. The phononic corner modes manifest within the frequency range of 5.0-5.4 THz, specifically in the frequency gap between the optical and acoustical phononic bands, for the 2D buckled arsenene. The topologically nontrivial behavior of the frequency gaps can be confirmed by the secondary topological index. In addition to the 0D phononic corner modes, 1D phononic edge modes also appear in the gap of the above frequency range. Therefore, this research establishes the foundation for future progress in the field of 2D topological phononics, specifically focusing on boundary states with multiple dimensions (1D and 0D).