Regensburg 1998 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
AM: Magnetismus
AM 11: Postersitzung
AM 11.17: Poster
Tuesday, March 24, 1998, 16:15–20:00, B
From one to two dimensions in quantum spin systems — •Mu-Sung Yang, Andreas Fledderjohann, Karl-Heinz Mütter, and Michael Karbach — Physics Department, University of Wuppertal, D-42097 Wuppertal, Germany
We study the first derivative of the staggered magnetization squared dm†(θ)2/dθ and the second derivative d2e0(θ)/dθ2 of the ground state energy per site. The parameter θ controls the anisotropy between horizontal and vertical couplings in a two-dimensional (2D) spin-1/2 antiferromagnetic Heisenberg model. It is shown, that both derivatives diverge at θ=1, where the anisotropic 2D model reduces to the 1D model.