Search results
Results from the WOW.Com Content Network
A type of quasiparticle in physics, [1] a phonon is an excited state in the quantum mechanical quantization of the modes of vibrations for elastic structures of interacting particles. Phonons can be thought of as quantized sound waves, similar to photons as quantized light waves. [2] The study of phonons is an important part of condensed matter ...
Non-linear phononics is the physics in solids created or triggered by large amplitude oscillations of phonons, [1] the elementary vibration of the crystal lattice. [2] [3] [4] It is an extension of the field of phononics, [5] which studies the regime of small harmonic vibrations and related phenomena in materials.
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.
Particle physicists have only observed or inferred left-chiral fermions and right-chiral antifermions engaging in the charged weak interaction. [1] In the case of the weak interaction, which can in principle engage with both left- and right-chiral fermions, only two left-handed fermions interact. Interactions involving right-handed or opposite ...
[1] [2] In nuclear physics, the chiral model, introduced by Feza Gürsey in 1960, is a phenomenological model describing effective interactions of mesons in the chiral limit (where the masses of the quarks go to zero), but without necessarily mentioning quarks at all.
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.
Figure 1. Schematic representation of the absorption line shape of an electronic excitation. The narrow component at the frequency ω′ is the zero-phonon line and the broader feature is the phonon sideband. In emission, the relative positions of the two components are mirrored about the center of the zero-phonon line at ω′.
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.