572 citations · 2.4k across the 24 of their papers we have counts for
23 papers
Optimizing multi-user indoor sound communications with acoustic reconfigurable metasurfaces
Hongkuan Zhang, Qiyuan Wang, Mathias Fink +1
Sound in indoor spaces forms a complex wavefield due to multiple scattering encountered by the sound. Indoor acoustic communication involving multiple sources and receivers thus in…
Non-Abelian physics in light and sound
Yi Yang, Biao Yang, Guancong Ma +3
There has been a recent surge of interest in using light and sound as platforms for studying non-Abelian physics. Through a kaleidoscope of physical effects, light and sound provid…
Realization of a Z classified chiral-symmetric higher-order topological insulator in a coupling-inversion acoustic crystal
Dongyi Wang, Yuanchen Deng, Mourad Oudich +3
Higher-order topological band theory has transformed the landscape of topological phases in quantum and classical systems. Here, we experimentally demonstrate a two-dimensional (2D…
Experimental realization of stable exceptional chains protected by non-Hermitian latent symmetries unique to mechanical systems
Xiaohan Cui, Ruo-Yang Zhang, Xulong Wang +3
Lines of exceptional points are robust in the 3-dimensional non-Hermitian parameter space without requiring any symmetry. However, when more elaborate exceptional structures are co…
Experimental Realization of Geometry-Dependent Skin Effect in a Reciprocal Two-Dimensional Lattice
Wei Wang, Mengying Hu, Xulong Wang +2
Recent studies of non-Hermitian periodic lattices unveiled the non-Hermitian skin effect (NHSE), in which the bulk modes under the periodic boundary conditions (PBC) become skin mo…
Realization and Topological Properties of Third-Order Exceptional Lines Embedded in Exceptional Surfaces
Weiyuan Tang, Kun Ding, Guancong Ma
As the counterpart of Hermitian nodal structures, the geometry formed by exceptional points (EPs), such as exceptional lines (ELs), entails intriguing spectral topology. We report…
Non-Hermitian eigenvalue knots and their isotopic equivalence
Zhen Li, Kun Ding, Guancong Ma
The spectrum of a non-Hermitian system generically forms a two-dimensional complex Riemannian manifold with distinct topology from the underlying parameter space. Spectral topology…
Non-Hermitian Topology and Exceptional-Point Geometries
Kun Ding, Chen Fang, Guancong Ma
Non-Hermitian theory is a theoretical framework that excels at describing open systems. It offers a powerful tool in the characterization of both the intrinsic degrees of freedom (…
Observation of degenerate zero-energy topological states at disclinations in an acoustic lattice
Yuanchen Deng, Wladimir A. Benalcazar, Ze-Guo Chen +3
Building upon the bulk-boundary correspondence in topological phases of matter, disclinations have recently been harnessed to trap fractionally quantized density of states (DoS) in…
Experimental Realization of Non-Abelian Permutations in a Three-State Non-Hermitian System
Weiyuan Tang, Kun Ding, Guancong Ma
Eigenstates of a non-Hermitian system exist on complex Riemannian manifolds, with multiple sheets connecting at branch cuts and exceptional points (EPs). These eigenstates can evol…
Non-Abelian braiding on photonic chips
Xu-Lin Zhang, Feng Yu, Ze-Guo Chen +4
Non-Abelian braiding has attracted significant attention because of its pivotal role in describing the exchange behaviors of anyons--a candidate for realizing quantum logics. The i…
Experimental Realization of Weyl Exceptional Rings in a Synthetic Three-Dimensional Non-Hermitian Phononic Crystal
Zheng-wei Li, Jing-jing Liu, Ze-Guo Chen +5
Weyl points (WPs) are isolated degeneracies carrying quantized topological charges, and are therefore robust against Hermitian perturbations. WPs are predicted to spread to the Wey…
Spin-orbit interactions of transverse sound
Shubo Wang, Guanqing Zhang, Xulong Wang +3
Spin-orbit interactions (SOIs) endow light with intriguing properties and applications such as photonic spin-Hall effects and spin-dependent vortex generations. However, it is coun…
Multi-dimensional wave steering with higher-order topological phononic crystal
Changqing Xu, Zeguo Chen, Guanqing Zhang +2
The recent discovery and realizations of higher-order topological insulators enrich the fundamental studies on topological phases. Here, we report three-dimensional (3D) wave-steer…
Relaying Topological Interface States for Negative Refraction of Bulk Waves
Hongchen Chu, Ze-Guo Chen, Yun Lai +1
Topological notions in physics have become a powerful perspective that leads to the discoveries of topological interface states (TISs). In this work, we present a scheme to achieve…
Direct Measurement of Topological Properties of an Exceptional Parabola
Weiyuan Tang, Kun Ding, Guancong Ma
Non-Hermitian systems can produce branch singularities known as exceptional points (EPs). Different from singularities in Hermitian systems, the topological properties of an EP can…
Landau-Zener Transition in Topological Acoustic Pumping
Ze-Guo Chen, Weiyuan Tang, Ruo-Yang Zhang +1
Quantized charge pumping is a robust adiabatic phenomenon uniquely existing in topologically nontrivial systems. Such topological pumping not only brings fundamental insights to th…
Four-Dimensional Higher-Order Chern Insulator and Its Acoustic Realization
Ze-Guo Chen, Weiwei Zhu, Yang Tan +2
We present a theoretical study and experimental realization of a system that is simultaneously a four-dimensional (4D) Chern insulator and a higher-order topological insulator (HOT…
Three-dimensional acoustic double-zero-index medium with a Dirac-like point
Changqing Xu, Guancong Ma, Ze-Guo Chen +4
We report a design and experimental realization of a three-dimensional (3D) acoustic double-zero-index medium (DZIM), whose effective mass density and compressibility are nearly ze…
Experimental demonstration of an anisotropic exceptional point
Kun Ding, Guancong Ma, Z. Q. Zhang +1
Exceptional points (EPs) associated with a square-root singularity have been found in many non-Hermitian systems. In most of the studies, the EPs found are isotropic meaning that t…
Topological transport of sound mediated by spin-redirection geometric phase
Shubo Wang, Guancong Ma, C. T. Chan
When a dynamic system undergoes a cyclic evolution, a geometric phase that depends only on the path traversed in parameter space can arise in addition to the normal dynamical phase…
Coexistence of quantized and non-quantized geometric phases in quasi-one-dimensional systems without inversion symmetry
Yi-Xin Xiao, Zhao-Qing Zhang, C. T. Chan
It is well known that inversion symmetry in one-dimensional (1D) systems leads to the quantization of the geometric Zak phase to values of either 0 or π. When the system has partic…
The emergence, coalescence and topological properties of multiple exceptional points and their experimental realization
Kun Ding, Guancong Ma, Meng Xiao +2
Non-Hermitian systems distinguish themselves from Hermitian systems by exhibiting a phase transition point called an exceptional point (EP), which is the point at which two eigenst…