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  2. Phonon - Wikipedia

    en.wikipedia.org/wiki/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 as phonons as long as the modal wavelength of the oscillation is smaller than the size of the object.

  3. Lyddane–Sachs–Teller relation - Wikipedia

    en.wikipedia.org/wiki/Lyddane–Sachs–Teller...

    Real phonons have losses (also known as damping or dissipation). Materials may have multiple phonon resonances that add together to produce the permittivity. There may be other electrically active degrees of freedom (notably, mobile electrons) and non-Lorentzian oscillators.

  4. Sound amplification by stimulated emission of radiation

    en.wikipedia.org/wiki/Sound_amplification_by...

    In other words, we need to calculate the energies (or frequencies ) of the phonons as a function of their wave vector's k. The relationship between frequency ω and wave vector k is called phonon dispersion. Light and sound are similar in various ways. They both can be thought of in terms of waves, and they both come in quantum mechanical units.

  5. Surface phonon - Wikipedia

    en.wikipedia.org/wiki/Surface_phonon

    Phonons take on both labels such that transverse acoustic and optical phonons are denoted TA and TO, respectively; likewise, longitudinal acoustic and optical phonons are denoted LA and LO. The type of surface phonon can be characterized by its dispersion in relation to the bulk phonon modes of the crystal.

  6. Polariton - Wikipedia

    en.wikipedia.org/wiki/Polariton

    A polariton is the result of the combination of a photon with a polar excitation in a material. The following are types of polaritons: Phonon polaritons result from coupling of an infrared photon with an optical phonon

  7. Glossary of music terminology - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_music_terminology

    At liberty (i.e. the speed and manner of execution are left to the performer. It can also mean improvisation.) adagietto Fairly slowly (but faster than adagio) adagio Slowly adagissimo Very, very slowly affannato, affannoso Anguished affetto or con affetto with affect (that is, with emotion) affettuoso, affettuosamente, or affectueusement (Fr.)

  8. Polaron - Wikipedia

    en.wikipedia.org/wiki/Polaron

    A polaron is a quasiparticle used in condensed matter physics to understand the interactions between electrons and atoms in a solid material. The polaron concept was proposed by Lev Landau in 1933 [1] and Solomon Pekar in 1946 [2] to describe an electron moving in a dielectric crystal where the atoms displace from their equilibrium positions to effectively screen the charge of an electron ...

  9. Phonon polariton - Wikipedia

    en.wikipedia.org/wiki/Phonon_polariton

    Optical phonons, by contrast, have a non-zero angular frequency at = and have a negative slope, which is also much smaller in magnitude to that of photons. This will result in the crossing of the optical phonon branch and the photon dispersion, leading to their coupling and the forming of a phonon polariton.