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The Correlation Function S zz (ω) for Weakly Coupled Impurity Atom Spin in a Ferromagnetic
Author(s) -
Krivoglaz M. A.,
Kvashnina L. B.
Publication year - 1968
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19680290105
Subject(s) - impurity , atom (system on chip) , spin (aerodynamics) , ferromagnetism , condensed matter physics , magnetic impurity , atomic physics , chemistry , physics , quantum mechanics , computer science , thermodynamics , embedded system
The closed chain of equations for the temperature Green's functions for the z ‐th component of the spin of an impurity atom in a ferromagnetic is obtained for the case of quasi‐local spin excitations in the neighbourhood of the impurity atom. The solution of this system is obtained in explicit form for the cases of high and low temperatures and of small values of the spin of the impurity atom ( S = 1/2, 1, 3/2). For these cases the spectral representation S zz (ω) of the correlation function 〈 S z ( t 1 ) − S z , S z ( t 2 ) − S z 〉 of the impurity atom spin is determined. It is pointed out that the quasi‐local spin states can result in a modulational broadening of the line of nuclear magnetic resonance some orders of magnitude larger than the broadening due to the spin waves in the perfect crystal.