Correlated cluster mean-field theory for Ising-like spin systems

The correlated cluster mean-field (CCMF) theory is an approximative method that have been applied to the study of spin-1/2 Hamiltonians, providing accurate results for several magnetic systems. In this paper, we review the method applications and extend its framework to the study of Ising-like systems with spin S > 1/2. Our investigation of the spin-1 ferromagnet on honeycomb, square and simple cubic lattices showed that the CCMF method results can be compared to state-of-the-art methods. We also present the method application for higher spin (3/2 <= S <= 5/2) and mixed-spin systems on the honeycomb lattice, comparing our findings with other techniques. As a result, the reduced critical temperature obtained within the CCMF theory overestimates by only 5% the exact result for the mixed spin-(1, 1/2) system. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The correlated cluster mean-field (CCMF) theory is an approximate method that has been applied to study spin-1/2 Hamiltonians and extended to Ising-like systems with spin S > 1/2. Research shows that the CCMF method results on honeycomb, square, and simple cubic lattices can be compared to state-of-the-art methods, and applications for higher spin and mixed-spin systems on the honeycomb lattice have been compared with other techniques. Results indicate that the reduced critical temperature obtained within the CCMF theory overestimates by only 5% the exact result for the mixed spin-(1, 1/2) system.