Time-varying media have recently emerged as a new paradigm for wave manipulation, due
to the synergy between the discovery of highly nonlinear materials, such as epsilon-near …

Metamaterials are rationally designed composites aiming at effective material parameters
that go beyond those of the ingredient materials. For example, negative metamaterial …

Out of equilibrium, a lack of reciprocity is the rule rather than the exception. Non-reciprocity
occurs, for instance, in active matter,,,,–, non-equilibrium systems,–, networks of neurons …

Originating from the studies of two-dimensional condensed-matter states, the concept of
topological order has recently been expanded to other fields of physics and engineering …

In the past 20 years, impressive progress has been made both experimentally and
theoretically in superconducting quantum circuits, which provide a platform for manipulating …

Reciprocity is a fundamental principle in optics, requiring that the response of a transmission
channel is symmetric when source and observation points are interchanged. It is of major …

We aim at providing a global perspective on electromagnetic nonreciprocity and clarifying
confusions that arose in recent developments of the field. We provide a general definition of …

Non-reciprocal transmission of motion is potentially highly beneficial to a wide range of
applications, ranging from wave guiding to shock and vibration dam** and energy …

Photonic time crystals are artificial materials whose electromagnetic properties are uniform
in space but periodically vary in time. The synthesis of these materials and experimental …

Acoustic metamaterials can manipulate and control sound waves in ways that are not
possible in conventional materials. Metamaterials with zero, or even negative, refractive …