Observation of D-class topology in an acoustic metamaterial.

Autor: Wu SQ; School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China; School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China; Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology, Foshan University, Foshan 528000, China., Cheng W; Department of Physics, University of Michigan, Ann Arbor MI 48109, USA., Liu XY; School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China., Wu BQ; School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China., Prodan E; Department of Physics, Yeshiva University, New York NY 10033, USA. Electronic address: prodan@yu.edu., Prodan C; Department of Physics and Engineering Physics, Fordham University, New York NY 10023, USA. Electronic address: cprodan@fordham.edu., Jiang JH; School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China; Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215123, China. Electronic address: jianhuajiang@suda.edu.cn.
Jazyk: angličtina
Zdroj: Science bulletin [Sci Bull (Beijing)] 2024 Apr 15; Vol. 69 (7), pp. 893-900. Date of Electronic Publication: 2024 Feb 01.
DOI: 10.1016/j.scib.2024.01.041
Abstrakt: Topological materials and metamaterials opened new paradigms to create and manipulate phases of matter with unconventional properties. Topological D-class phases (TDPs) are archetypes of the ten-fold classification of topological phases with particle-hole symmetry. In two dimensions, TDPs support propagating topological edge modes that simulate the elusive Majorana elementary particles. Furthermore, a piercing of π-flux Dirac-solenoids in TDPs stabilizes localized Majorana excitations that can be braided for the purpose of topological quantum computation. Such two-dimensional (2D) TDPs have been a focus in the research frontier, but their experimental realizations are still under debate. Here, with a novel design scheme, we realize 2D TDPs in an acoustic crystal by synthesizing both the particle-hole and fermion-like time reversal symmetries for a wide range of frequencies. The design scheme leverages an enriched unit cell structure with real-valued couplings that emulate the targeted Hamiltonian of TDPs with complex hoppings: A technique that could unlock the realization of all topological classes with passive metamaterials. In our experiments, we realize a pair of TDPs with opposite Chern numbers in two independent sectors that are connected by an intrinsic fermion-like time-reversal symmetry built in the system. We measure the acoustic Majorana-like helical edge modes and visualize their robust topological transport, thus revealing the unprecedented D and DIII class topologies with direct evidence. Our study opens up a new pathway for the experimental realization of two fundamental classes of topological phases and may offer new insights in fundamental physics, materials science, and phononic information processing.
(Copyright © 2024 Science China Press. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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