BACKGROUND Singularities are critical points for which the behavior of a mathematical
model governing a physical system is of a fundamentally different nature compared to the …

In the past few years, concepts from non-Hermitian (NH) physics, originally developed within
the context of quantum field theories, have been successfully deployed over a wide range of …

Asymmetric coupling amplitudes effectively create an imaginary gauge field, which induces
a non-Hermitian Aharonov-Bohm (AB) effect. Nonzero imaginary magnetic flux invalidates …

Topological operations around exceptional points,,,,,,–—time-varying system configurations
associated with non-Hermitian singularities—have been proposed as a robust approach to …

It is generally assumed that a Hamiltonian for a physically acceptable quantum system (one
that has a positive-definite spectrum and obeys the requirement of unitarity) must be …

The exceptional points (EPs) of non-Hermitian systems, where n different energy
eigenstates merge into an identical one, have many intriguing properties that have no …

Photoluminescence including fluorescence plays a great role in a wide variety of
applications from biomedical sensing and imaging to optoelectronics. Therefore, the …

Excitons in lead bromide perovskites exhibit high binding energy and high oscillator
strength, allowing for a strong light‐matter coupling regime in the perovskite‐based cavities …

Exceptional point and spectral singularity are two types of singularity that are unique to non-
Hermitian systems. Here, we report the high-order spectral singularity as a high-order pole …

Electromagnetic waves propagating in conventional wave-guiding structures are reflected
by discontinuities and decay in lossy regions. In this Letter, we drastically modify this typical …