2017/12/31 by Jin-Wu Jiang, Bing-Shen Wang, Harold S. Park · 33 citations
Materials Science · Physics and Astronomy · #Boron nitride #Graphene research and applications #Hexagonal boron nitride #Hexagonal lattice #Lattice (music) #Molecular dynamics #Phonon #Point reflection #Silicon #Silicon carbide #Thermal properties of materials #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1039/c8nr04314k
published in Nanoscale 10(29), 13913-13923 (Royal Society of Chemistry) · Nanoscale, accepted
openalex publication_date 2018/01/01 · openalex created_date 2018/07/19 · arxiv created 2018/07/23 · arxiv updated 2018/08/07 · openalex updated_date 2026/08/05
We perform both lattice dynamics analysis and molecular dynamics simulations to demonstrate the existence of topologically protected phonon modes in two-dimensional, monolayer hexagonal boron nitride and silicon carbide sheets. The topological phonon modes are found to be localized at an in-plane interface that divides these systems into two regions of distinct valley Chern numbers. The dispersion of this topological phonon mode crosses over the frequency gap, which is opened through analogy with the quantum valley Hall effect by breaking the inversion symmetry of the primitive unit cells. Consequently, vibrational energy with frequency within this gap is topologically protected, resulting in wave propagation that exhibits minimal backscattering, is robust with regard to structural defects such as sharp corners, and exhibits excellent temporal stability. Our findings open up the possibility of actuating and detecting topological phonons in two-dimensional nanomaterials.