Weyl and Dirac semimetals are three-dimensional phases of matter with gapless electronic
excitations that are protected by topology and symmetry. As three-dimensional analogs of …

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 …

While Hermiticity lies at the heart of quantum mechanics, recent experimental advances in
controlling dissipation have brought about unprecedented flexibility in engineering non …

Topological materials have become the focus of intense research in recent years, since they
exhibit fundamentally new physical phenomena with potential applications for novel devices …

INTRODUCTION Physical systems that exhibit topological invariants are naturally endowed
with robustness against perturbations, as was recently demonstrated in many settings in …

Topological insulators are a new phase of matter, with the striking property that conduction
of electrons occurs only on their surfaces,,. In two dimensions, electrons on the surface of a …

Over the past decade, topology has emerged as a major branch in broad areas of physics,
from atomic lattices to condensed matter. In particular, topology has received significant …

The law of reciprocity in acoustics and elastodynamics codifies a relation of symmetry
between action and reaction in fluids and solids. In its simplest form, it states that the …

Let there be light–to change the world we want to be! Over the past several decades, and
ever since the birth of the first laser, mankind has witnessed the development of the science …

Topological photonics is a rapidly emerging field of research in which geometrical and
topological ideas are exploited to design and control the behavior of light. Drawing …