2018/08/31 by Xin Li, Yan Meng, Xiaoxiao Wu +4 · 89 citations
Mathematics · Physics and Astronomy · #Condensed matter physics #Geometry #Mathematics #Optics #Phase (matter) #Phase transition #Physics #Quantum many-body systems #Quantum mechanics #Random lasers and scattering media #Resonator #Symmetry (geometry) #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.mes-hall #physics.class-ph
paper · pdf · doi:10.1063/1.5051523
published in Applied Physics Letters 113(20) (American Institute of Physics) · 20 pages, 6 figures
openalex created_date 2018/08/31 · arxiv created 2018/10/25 · openalex publication_date 2018/11/12 · arxiv updated 2018/11/26 · openalex updated_date 2026/08/05
If a full bandgap closes and then reopens when we continuously deform a periodic system while keeping its symmetry, a topological phase transition usually occurs. A common model demonstrating such a topological phase transition in condensed matter physics is the Su-Schrieffer-Heeger (SSH) model. As is well known, two distinct topological phases emerge when the intracell hopping is tuned from smaller to larger with respect to the intercell hopping in the model. The former case is topologically trivial, while the latter case is topologically non-trivial. Here, we design a 1D periodic acoustic system in exact analogy with the SSH model. The unit cell of the acoustic system is composed of two resonators and two junction tubes connecting them. We show that the topological phase transition happens in our acoustic analog when we tune the radii of the junction tubes which control the intercell and intracell hoppings. The topological phase transition is characterized by the abrupt change in the geometric Zak phase. The topological interface states between non-trivial and trivial phases of our acoustic analog are experimentally measured, and the results agree very well with the numerical values. Furthermore, we show that topologically non-trivial phases of our acoustic analog of the SSH model can support edge states, on which the discussion is absent in previous works about topological acoustics. The edge states are robust against localized defects and perturbations.