Optical physics

Physics

Optomechanics

Symmetry (geometry)

Mathematics

Hermitian matrix

Statistics

Geometry

Parity (physics)

Theoretical physics

Quantum mechanics

Realization (probability)

Plasma

Modern physics

Quantum

Nature Physics

In recent years, notions drawn from non-Hermitian physics and parity–time (PT) symmetry have attracted considerable attention. In particular, the realization that the interplay between gain and loss can lead to entirely new and unexpected features has initiated an intense research effort to explore non-Hermitian systems both theoretically and experimentally. Here we review recent progress in this emerging field, and provide an outlook to future directions and developments. This Review Article outlines the exploration of the interplay between parity–time symmetry and non-Hermitian physics in optics, plasmonics and optomechanics.

Non-Hermitian physics and PT symmetry