n.
In solid-state physics , a quantum of lattice vibrational energy.
In analogy to a photon (a quantum of light), a phonon is viewed as a wave packet with particlelike properties (see wave-particle duality ). The way phonons behave determines or affects various properties of solids . Thermal conductivity, for instance, is explained by phonon interactions. Phonons also provide the basis for understanding superconductivity in certain metals.