QUANTUM CORRELATION-EFFECTS IN THE SPIN DYNAMICS OF GD AT HIGH-TEMPERATURES IN THE LIGHT OF COMPLEX DILATION THEORY

Recent experimental results on spin dynamics of Gd at high temperatures above Tc [J. W. Cable and R. M. Nicklow, Phys. Rev. B 39, 11 732 (1989)] are analyzed in the context of general quantum correlation theory of condensed disordered matter. The theory is based on the fermionic second-order density matrix in connection with complex dilation and thermalization. Assuming the validity of this theory a confrontation with the aforementioned experimental data leads to the conclusion that the spatial extension of the quantum correlations characterizing the considered system is independent of temperature between T=320 and 850 K. The analysis further suggests that the dimension of the magnetically ordered regions is independent of T in the considered range. © 1990 The American Physical Society.