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Magnetic dipole–dipole interaction, also called dipolar coupling, refers to the direct interaction between two magnetic dipoles. Roughly speaking, the magnetic field of a dipole goes as the inverse cube of the distance, and the force of its magnetic field on another dipole goes as the first derivative of the magnetic field. It follows that ...
It is related to the prototypical Ising model, where at each site of a lattice, a spin {} represents a microscopic magnetic dipole to which the magnetic moment is either up or down. Except the coupling between magnetic dipole moments, there is also a multipolar version of Heisenberg model called the multipolar exchange interaction .
Box A has no coupling. The dispersion relation shows 2 shifted free space dispersion relations. Box B shows how the gap at k=0 opens for weak coupling. Box C shows the strong coupling limit where the double degenerate minima in the first band merge into a single ground state at k=0.
A key example of this phenomenon is the spin–orbit interaction leading to shifts in an electron's atomic energy levels, due to electromagnetic interaction between the electron's magnetic dipole, its orbital motion, and the electrostatic field of the positively charged nucleus.
In physics, polaritons / p ə ˈ l ær ɪ t ɒ n z, p oʊ-/ [1] 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 exciton).
The interaction was first derived by Enrico Fermi in 1930. [7] A classical derivation of this term is contained in "Classical Electrodynamics" by J. D. Jackson. [8] In short, the classical energy may be written in terms of the energy of one magnetic dipole moment in the magnetic field B(r) of another dipole.
More specifically, we shall derive an analytical expression for the strength of the inter-dot Foerster coupling. It can be also shown that this coupling is, under certain conditions, of dipole-dipole type and that it is responsible for resonant exciton exchange between adjacent QD's. This is a transfer of energy only, not a tunnelling effect.
In nuclear chemistry and nuclear physics, J-couplings (also called spin-spin coupling or indirect dipole–dipole coupling) are mediated through chemical bonds connecting two spins. It is an indirect interaction between two nuclear spins that arises from hyperfine interactions between the nuclei and local electrons. [ 1 ]