In quantum mechanics, the procedure of constructing eigenstates of total angular momentum out of eigenstates of separate angular momenta is called angular momentum coupling. For instance, the orbit and spin of a single particle can interact through spin-orbit interaction, in which case the complete physical picture must include spin-orbit coupling. Or two charged particles, each with a well-defined angular momentum, may interact by Coulomb forces, in which case coupling of the two one-particle angular momenta to a total angular momentum is a useful step in the solution of the two-particle Schrödinger equation. In both cases the separate angular momenta are no longer constants of motion, but the sum of the two angular momenta usually still is. Angular momentum coupling in atoms is of importance in atomic spectroscopy. Angular momentum coupling of electron spins is of importance in quantum chemistry. Also in the nuclear shell model angular momentum coupling is ubiquitous.
In astronomy, spin-orbit coupling reflects the general law of conservation of angular momentum, which holds for celestial systems as well. In simple cases, the direction of the angular momentum vector is neglected, and the spin-orbit coupling is the ratio between the frequency with which a planet or other celestial body spins about its own axis to that with which it orbits another body. This is more commonly known as orbital resonance. Often, the underlying physical effects are tidal forces.
Read more about Angular Momentum Coupling: Spin-orbit Coupling, Spin-spin Coupling, Term Symbols, Relativistic Effects, Nuclear Coupling
Other articles related to "angular momentum, angular momentum coupling, coupling":
... and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei ... Spin is one of two types of angular momentum in quantum mechanics, the other being orbital angular momentum ... Orbital angular momentum is the quantum-mechanical counterpart to the classical notion of angular momentum it arises when a particle executes a rotating or twisting trajectory (such as when an ...
... In particular, the direction of the angular momentum of the photons would set the magnetization direction without the need of an external magnetic field ... The only difference is that now, the angular momentum is supplied by the circularly polarized photons instead of the polarized electrons ... In quantum field theory and quantum chemistry the effect where the angular momentum associated to the circular motion of the photons induces an angular momentum in the electrons is called photomagneton ...
... All nuclear levels whose l value (orbital angular momentum) is greater than zero are thus split in the shell model to create states designated by l + s and l − s ...
... Often, two or more sorts of angular momentum interact with each other, so that angular momentum can transfer from one to the other ... For example, in spin-orbit coupling, angular momentum can transfer between L and S, but only the total J=L+S is conserved ... example, in an atom with two electrons, each has its own angular momentum J1 and J2, but only the total J=J1+J2 is conserved ...
... Spin obeys commutation relations analogous to those of the orbital angular momentum where is the Levi-Civita symbol ... It follows (as with angular momentum) that the eigenvectors of S2 and Sz (expressed as kets in the total S basis) are The spin raising and lowering operators ... The total angular momentum conserved in interaction processes is then the sum of the orbital angular momentum and the spin ...
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