Non-Hermitian systems are physical systems whose effective Hamiltonians or dynamical generators are not equal to their Hermitian conjugates, leading to complex eigenvalues and non-orthogonal eigenstates. They naturally model open, dissipative, or gain–loss systems where energy or probability is not conserved, such as in photonics, acoustics, and cold-atom platforms. Non-Hermitian systems exhibit distinctive phenomena including exceptional points, non-Hermitian skin effects, and modified bulk–boundary correspondence, often described using biorthogonal bases. They are analyzed via non-Hermitian extensions of quantum and wave theories, with particular attention to spectral properties, stability, and the role of symmetries such as parity–time (PT) symmetry.
Exceptional points (EPs) are non-Hermitian singularities where two or more eigenstates coalesce, resulting in the eigenspace collapsing in dimensionality. Over the past decade, researchers have uncovered a wealth of exotic ...
Optics & Photonics
Nov 26, 2025
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A research team has observed multibody interaction-induced EPs and hysteresis trajectories in cold Rydberg atomic gases. They revealed the phenomenon of charge-conjugation parity (CP) symmetry breaking in non-Hermitian multibody ...
General Physics
Jun 11, 2025
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Exceptional points (EPs) are unique types of energy-level degeneracies that occur in non-Hermitian systems. Since their existence was first proposed more than a century ago, physicists have only been able to experimentally ...
A research team led by The Hong Kong University of Science and Technology (HKUST) has achieved a groundbreaking quantum simulation of the non-Hermitian skin effect in two dimensions using ultracold fermions, marking a significant ...
Condensed Matter
Jan 8, 2025
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The spectral degeneracies emerging as a consequence of parity-time (PT) symmetry exhibit a profound divergence from their conventional counterparts. They possess non-Hermitian nature and are designated as exceptional points ...
Optics & Photonics
Sep 12, 2024
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In a new Physical Review Letters study, scientists have demonstrated the first experimental observation of non-Hermitian edge burst in quantum dynamics using a carefully designed photonic quantum walk setup.
A study, published in the journal Science Bulletin and led by Dr. Haiping Hu from the Institute of Physics, Chinese Academy of Sciences (IOP, CAS), explores the non-Hermitian skin effect (NHSE) and non-Bloch bands.
Condensed Matter
Aug 30, 2024
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134
In recent years, advances in photonics and materials science have led to remarkable developments in sensor technology, pushing the boundaries of what can be detected and measured. Among these innovations, non-Hermitian physics ...
Optics & Photonics
Aug 27, 2024
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An international team of scientists, including two researchers who now work in the Center for Advanced Sensor Technology (CAST) at UMBC, has shown that twisted carbon nanotubes can store three times more energy per unit mass ...
Nanomaterials
Jul 26, 2024
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547
Using two optically-trapped glass nanoparticles, researchers observed a novel collective Non-Hermitian and non-linear dynamic driven by non-reciprocal interactions. This contribution expands traditional optical levitation ...
Optics & Photonics
Jul 25, 2024
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