Topological electronic materials, such as topological insulators, are distinct from trivial
materials in the topology of their electronic band structures that lead to robust …

The importance of global band topology is unequivocally recognized in condensed matter
physics, and new states of matter, such as topological insulators, have been discovered …

Directional transport and propagation of quantum particle and current, such as electron,
photon, spin, and phonon, are known to occur in the materials system with broken inversion …

Axions are hypothetical particles that were proposed to solve the strong charge–parity
problem in high-energy physics. Although they have long been known in quantum field …

Helical spin structures are expressions of magnetically induced chirality, entangling the
dipolar and magnetic orders in materials,,–. The recent discovery of helical van der Waals …

Magnon polarons are novel elementary excitations possessing hybrid magnonic and
phononic signatures, and are responsible for many exotic spintronic and magnonic …

The properties of transition metal compounds are largely determined by nontrivial interplay
of different degrees of freedom: charge, spin, lattice, and also orbital ones. Especially rich …

The nonreciprocal magnetoelectric effect, also known as the Tellegen effect, promises a
number of groundbreaking phenomena connected to fundamental (eg, electrodynamics of …

We present a terahertz spectroscopic study of polar ferrimagnet FeZnMo 3 O 8. Our main
finding is a giant high-temperature optical diode effect, or nonreciprocal directional …

The Maxwell equations and the constitutive relations describe the classical propagation of
electromagnetic waves in continuous matter. Here, we investigate the effects stemming from …