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 …

Since its birth in the 1920s, quantum mechanics has motivated and advanced the analysis of
linear operators. In this effort, it significantly contributed to the development of sophisticated …

Exceptional point degeneracies (EPD) of linear non-Hermitian systems have been recently
utilized for hypersensitive sensing. This proposal exploits the sublinear response that the …

A common wisdom in quantum mechanics is that the Hamiltonian has to be Hermitian in
order to ensure a real eigenvalue spectrum. Yet, parity–time (PT)-symmetric Hamiltonians …

The scalar field theory with potential V (φ)= 1 2 m 2 φ 2-1 4 g φ 4 (g> 0) is ill defined as a
Hermitian theory but in a non-Hermitian PT-symmetric framework it is well defined, and it has …

Polaritons are widely investigated quasiparticles with fundamental and technological
significance due to their unique properties. They have been studied most extensively in …

The past few years have witnessed a surge of interest in non-Hermitian Floquet topological
matter due to its exotic properties resulting from the interplay between driving fields and non …

Recently, apparent nonphysical implications of non-Hermitian quantum mechanics (NHQM)
have been discussed in the literature. In particular, the apparent violation of the no-signaling …

A longstanding tool to characterize the evolution of open Markovian quantum systems is the
GKSL (Gorini-Kossakowski-Sudarshan-Lindblad) master equation. However, in some cases …

Exceptional points (EPs) have recently emerged as a new method for engineering the
response of open physical systems, that is, systems that interact with the environment. The …