Natural and human environments are abundant of unused renewable energy such as
mechanical energy, acoustic energy, electromagnetic energy, thermal energy, etc. The idea …

The unique conduction properties of condensed matter systems with topological order have
recently inspired a quest for the similar effects in classical wave phenomena. Acoustic …

Topological phononic states, which facilitate unique acoustic transport around defects and
disorders, have significantly revolutionized our scientific cognition of acoustic systems. Here …

The discovery of topological insulators was rapidly followed by the advent of their photonic
analogues, motivated by the prospect of backscattering‐immune light propagation. So far …

Classical wave fields are real-valued, ensuring the wave states at opposite frequencies and
momenta to be inherently identical. Such a particle–hole symmetry can open up new …

Here, we show that space-time modulations provide an exciting route to realize complex
nonreciprocal couplings, and, in particular, the elusive axion response. We develop an …

That disorder can induce nontrivial topology is a surprising discovery in topological physics.
As a typical example, Chern topological Anderson insulators (TAIs) have been realized in …

We investigate a two-way waveguide constructed by bringing close two identical magneto-
optical photonic crystals which each supports a counterpropagating topological one-way …

We present a new electromagnetic mode that forms at the interface between two planar
surfaces laid side by side in free space, effectively guiding energy along an infinitesimal …

Planar junctions between reactive surface impedances with dual character
(capacitive/inductive) can sustain line waves localized both in-plane and out-of-plane …