Open AccessОбменные и обменно-релятивистские эффекты в возбужденных состояниях 3d-ионов в кристаллах
Author(s) -
А.С. Москвин
Publication year - 2019
Publication title -
fizika tverdogo tela
Language(s) - English
Resource type - Journals
eISSN - 1726-7498
pISSN - 0367-3294
DOI - 10.21883/ftt.2019.05.47605.18f
Subject(s) - superexchange , physics , hamiltonian (control theory) , exchange interaction , excited state , ferromagnetism , spin (aerodynamics) , excitation , degeneracy (biology) , quantum mechanics , mathematics , mathematical optimization , bioinformatics , biology , thermodynamics
The use of the simplest Heisenberg or Dzyaloshinskii–Moriya-type spin Hamiltonians traditional for the ground orbital nondegenerate states does not allow the features of the exchange and exchange-relativistic couplings for the excited states of 3 d and 4 f ions in crystals to be correctly described. We have considered a generalized Hamiltonian of the exchange and superexchange couplings, which makes it possible to take into account the effects of orbital (quasi)degeneracy and the exchange mechanism of excitation transfer using a single approach. A new mechanism of the spin–other orbit exchange-relativistic couplings is discussed, in particular, the spin–orbital analog of the Dzyaloshinskii–Moriya interaction and its manifestation in the circular magnetooptics of weak ferromagnets.