Decomposition of Ising spin of spin-S Ising model

K. Nomura

We study the spin-correlation functions of the one-dimensional S=1 antiferromagnetic Heisenberg-Ising model by the large-cluster-decomposition Monte Carlo method. It is found that this model shows a second-order transition at the anisotropy parameter ${\ensuremath{\lambda}}_{c}$=1.167\ifmmode\pm\else\textpm\fi{}0.007. The obtained critical exponents (\ensuremath{\eta}=0.253\ifmmode\pm\else\textpm\fi{}0.002, \ensuremath{\beta}=0.126\ifmmode\pm\else\textpm\fi{}0.007, \ensuremath{\nu}=0.98\ifmmode\pm\else\textpm\fi{}0.02) strongly suggest that this transition belongs to the same universality class as the two-dimensional Ising model.

Hiroshi Mamada, F. Takano

Yang, Zhi-Hua, Li‐Ping Yang, Haina Wu +2 more

This is a supplementary material of our recent paper\cite{yangPRB}, where a class of exactly solvable S=1 quantum Ising spin models were studied based on the hole decomposition scheme. Here we provide some details for the Green functions, the spin-spin correlation functions, as well as the spin susceptibility in the presence of dimerization.

Hadey K. Mohamad

B. Frank, K. Nath

A method is found whereby the product average decomposition (PAD) approximation of Frank and Mitran may be directly applied to the thermal average of any well-behaved function of Oi = ΣjJijSj, for the spin-1/2 Ising model with nearest-neighbour interactions. A general formula is derived by considering a fictitious spin system wherein the PAD is exact. It is applied to the calculation of transition temperatures in d dimensions, for d = 3 to d = 20.

Fa Yueh Wu