Advanced finite-temperature Lanczos method for anisotropic spin systems
Department of Physics, Bielefeld University, P.O. box 100131, 33501 Bielefeld, Germany
Received: 3 June 2014
Received in final form: 2 July 2014
Published online: 3 September 2014
It is virtually impossible to evaluate the magnetic properties of large anisotropic magnetic molecules numerically exactly due to the huge Hilbert space dimensions as well as due to the absence of symmetries. Here we propose to advance the finite-temperature Lanczos method (FTLM) to the case of single-ion anisotropy. The main obstacle, namely the loss of the spin rotational symmetry about the field axis, can be overcome by choosing symmetry related random vectors for the approximate evaluation of the partition function. We demonstrate that now thermodynamic functions for anisotropic magnetic molecules of unprecedented size can be evaluated.
Key words: Computational Methods
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014