Surface magnon-polaritons (SMPs) are a type of

quasiparticle In condensed matter physics, a quasiparticle is a concept used to describe a collective behavior of a group of particles that can be treated as if they were a single particle. Formally, quasiparticles and collective excitations are closely relate ...

condensed matter physics Condensed matter physics is the field of physics that deals with the macroscopic and microscopic physical properties of matter, especially the solid and liquid State of matter, phases, that arise from electromagnetic forces between atoms and elec ...

. They arise from the coupling of incident electromagnetic (EM) radiations to the

magnetic dipole In electromagnetism, a magnetic dipole is the limit of either a closed loop of electric current or a pair of poles as the size of the source is reduced to zero while keeping the magnetic moment constant. It is a magnetic analogue of the Electri ...

polarization in the surface layers of a solid.

Magnon A magnon is a quasiparticle, a collective excitation of the spin structure of an electron in a crystal lattice. In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. Magnons carry a fixed amou ...

s are analogous to other forms of

polariton In physics, polaritons are bosonic quasiparticles resulting from strong coupling of electromagnetic waves (photon) with an electric or magnetic dipole-carrying excitation (state) of solid or liquid matter (such as a phonon, plasmon, or an exc ...

s, such as

plasmon In physics, a plasmon is a quantum of plasma oscillation. Just as light (an optical oscillation) consists of photons, the plasma oscillation consists of plasmons. The plasmon can be considered as a quasiparticle since it arises from the quant ...

s and

phonon A phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, specifically in solids and some liquids. In the context of optically trapped objects, the quantized vibration mode can be defined a ...

s, but represent an oscillation of the magnetic component of the solid's EM field rather than its electric component or a mechanical oscillation in the solid's atomic structure. They are sometimes referred to as magnetic surface polaritons (MSPs). By employing artificially constructed

metamaterial A metamaterial (from the Greek word μετά ''meta'', meaning "beyond" or "after", and the Latin word ''materia'', meaning "matter" or "material") is a type of material engineered to have a property, typically rarely observed in naturally occu ...

s whose properties mainly stem from their engineered internal fine structures rather than their bulk physical make up, it is possible to more easily achieve useful SMPs. However, they can be found in several natural magnetic materials, including at THz frequencies in antiferromagnetic crystals. Magnons offer a way to control light-matter interactions at Terahertz frequencies.

References

{{CMP-stub Quasiparticles Plasmonics