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Hopfield dielectric – in quantum mechanics a model of dielectric consisting of quantum harmonic oscillators interacting with the modes of the quantum electromagnetic field. The collective interaction of the charge polarization modes with the vacuum excitations, photons leads to the perturbation of both the linear dispersion relation of photons and constant dispersion of charge waves by the avoided crossing between the two dispersion lines of polaritons. Similarly to the acoustic and the optical phonons and far from the resonance one branch is photon-like while the other charge wave-like. Mathematically the Hopfield dielectric for the one mode of excitation is equivalent to the Trojan wave packet in the harmonic approximation. The Hopfield model of the dielectric predicts the existence of eternal trapped frozen photons similar to the Hawking radiation inside the matter with the density proportional to the strength of the matter-field coupling. ==Theory== The Hamiltonian of the quantized Lorentz dielectric consisting of harmonic oscillators interacting with the quantum electromagnetic field can be written in the dipole approximation as: : Assuming oscillators to be on some kind of the regular solid lattice and applying the polaritonic Fourier transform : : and defining projections of oscillator charge waves onto the electromagnetic field polarization directions : : after dropping the longitudinal contributions not interacting with the electromagnetic field one may obtain the Hopfield Hamiltonian : Because the interaction is not mixing polarizations this can be transformed to the normal form with the eigen-frequencies of two polaritonic branches: : with the eigenvalue equation : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Hopfield dielectric」の詳細全文を読む スポンサード リンク
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