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 …

The topological properties of an object, associated with an integer called the topological
invariant, are global features that cannot change continuously but only through abrupt …

The concept of topological energy bands and their manifestations have been demonstrated
in condensed matter systems as a fantastic paradigm toward unprecedented physical …

Backscattering suppression in silicon-on-insulator (SOI) is one of the central issues to
reduce energy loss and signal distortion, enabling for capability improvement of modern …

In solid state physics, a bandgap (BG) refers to a range of energies where no electronic
states can exist. This concept was extended to classical waves, spawning the entire fields of …

Recently, we witnessed a tremendous effort to conquer the realm of acoustics as a possible
playground to test with topologically protected sound wave propagation. In this article, we …

Valley topological materials, in which electrons possess valley pseudospin, have attracted a
growing interest recently. The additional valley degree of freedom offers a great potential for …

Topologically gapless edge states, characterized by topological invariants and Berry's
phases of bulk energy bands, provide amazing techniques to robustly control the …

The introduction of engineered resonance phenomena on surfaces has opened a new
frontier in surface science and technology. Pillared phononic crystals, metamaterials, and …

Effective manipulation of phonons is crucial to modern energy‐information science and
technologies but limited by the charge neutral and spinless nature of phonons. Recently …