Open AccessTheoretical Models for Magnetic Properties of Iron Pnictides Part II: Boson Formalism
Author(s) -
M. Vujinović,
M. Pantić,
Milica Pavkov-Hrvojević,
Petar Mali
Publication year - 2011
Publication title -
journal of research in physics
Language(s) - English
Resource type - Journals
eISSN - 2217-933X
pISSN - 1450-7404
DOI - 10.2478/v10242-012-0004-0
Subject(s) - hamiltonian (control theory) , formalism (music) , boson , physics , wave function , random phase approximation , heisenberg model , condensed matter physics , ground state , hamiltonian formalism , spin wave , magnetization , quantum mechanics , ferromagnetism , magnetic field , mathematics , art , mathematical optimization , musical , covariant transformation , visual arts
Theoretical Models for Magnetic Properties of Iron Pnictides Part II: Boson Formalism We analyze the J 1 - J 2 - J c Heisenberg model Hamiltonian by using the Dyson-Maleev representation for spin operators and keeping the terms quadratic in Bose operators (linear spin wave theory). From the resulting Hamiltonian we find the ground state magnetisation and spin wave dispersion by employing the Green's function method. We compare the results with those of random phase approximation analysis from Part I and with experimental data for parent pnictide compounds. Neither of the two approaches gives a completely satisfactory description of the magnetic properties of iron pnictides. We conclude that alterations of the model Hamiltonian are needed to get a better agreement between the theory and experiments.