1302.0691 (Ümit Ak\incı)

Random field effects on the isotropic quantum Heisenberg model with
Gaussian random magnetic field distribution    [PDF]

Ümit Ak\incı

Effect of Gaussian random magnetic field distribution which is centered at zero on the phase transition properties of isotropic quantum Heisenberg model has been investigated on two (2D) and three dimensional (3D) lattices within the framework of effective field theory (EFT) for a two spin cluster (which is abbreviated as EFT-2). Beside the phase diagrams and the evolution of the magnetization versus temperature curves with the Gaussian magnetic field distribution width, critical Gaussian distribution width values, which make the critical temperature zero, have been obtained for several lattices. Moreover, it has been concluded that all critical temperatures are of the second order and reentrant behavior does not exist in the phase diagrams.

View original: http://arxiv.org/abs/1302.0691