Non-Hermitian topology and exceptional-point geometries
Non-Hermitian theory is a theoretical framework used to describe open systems. It offers a
powerful tool in the characterization of both the intrinsic degrees of freedom of a system and …
powerful tool in the characterization of both the intrinsic degrees of freedom of a system and …
Various topological phases and their abnormal effects of topological acoustic metamaterials
The last 20 years have witnessed growing impacts of the topological concept on the
branches of physics, including materials, electronics, photonics, and acoustics. Topology …
branches of physics, including materials, electronics, photonics, and acoustics. Topology …
Homotopy, symmetry, and non-Hermitian band topology
Non-Hermitian matrices are ubiquitous in the description of nature ranging from classical
dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering …
dissipative systems, including optical, electrical, and mechanical metamaterials, to scattering …
Non-Hermitian swallowtail catastrophe revealing transitions among diverse topological singularities
Exceptional points are a unique feature of non-Hermitian systems at which the eigenvalues
and corresponding eigenstates of a Hamiltonian coalesce. Many intriguing physical …
and corresponding eigenstates of a Hamiltonian coalesce. Many intriguing physical …
Experimental simulation of symmetry-protected higher-order exceptional points with single photons
Exceptional points (EPs) of non-Hermitian (NH) systems have recently attracted increasing
attention due to their rich phenomenology and intriguing applications. Compared to the …
attention due to their rich phenomenology and intriguing applications. Compared to the …
Eigenvalue knots and their isotopic equivalence in three-state non-Hermitian systems
The spectrum of a non-Hermitian system generically forms a two-dimensional complex
Riemannian manifold with a distinct topology from the underlying parameter space. This …
Riemannian manifold with a distinct topology from the underlying parameter space. This …
Experimental characterization of three-band braid relations in non-Hermitian acoustic lattices
The nature of complex eigenenergy enables unique band topology in non-Hermitian (NH)
lattices. Recently, there has been fast growing interest in the elusive winding and braiding …
lattices. Recently, there has been fast growing interest in the elusive winding and braiding …
Topological phase diagrams of exactly solvable non-Hermitian interacting Kitaev chains
Many-body interactions give rise to the appearance of exotic phases in Hermitian physics.
Despite their importance, many-body effects remain an open problem in non-Hermitian …
Despite their importance, many-body effects remain an open problem in non-Hermitian …
Realization and topological properties of third-order exceptional lines embedded in exceptional surfaces
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 the …
(EPs), such as exceptional lines (ELs), entails intriguing spectral topology. We report the …
Protection of all nondefective twofold degeneracies by antiunitary symmetries in non-Hermitian systems
S Sayyad - Physical Review Research, 2022 - APS
Non-Hermitian degeneracies are classified as defective exceptional points (EPs) and
nondefective degeneracies. While in defective EPs, both eigenvalues and eigenvectors …
nondefective degeneracies. While in defective EPs, both eigenvalues and eigenvectors …