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Santos, Onofre Rojas; Salvador, Juan Segundo Valverde; Souza, Sergio Martins de
(2009)
The paper discusses the transformation of decorated Ising models into an effective undecorated spin model, using the most general Hamiltonian for interacting Ising models including a long range and high order interactions. ...
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Salvador, Juan Segundo Valverde; Santos, Onofre Rojas; Souza, Sergio Martins de
(2008)
Geometrically frustrated spin models with competing interaction parameters and the phase diagram of their corresponding T = 0 ground state energies are studied. The partition function defined by means of the transfer ...
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Salvador, Juan Segundo Valverde; Santos, Onofre Rojas; Souza, Sergio Martins de
(2008)
The asymmetric tetrahedron is composed of all edges of a tetrahedron represented by Ising interactions except for one, which has a Heisenberg-type interaction. This asymmetric tetrahedron is arranged by connecting a vertex ...
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Valverde, Juan Segundo; Souza, Sergio Martins de; Santos, Onofre Rojas
(2009)
We study a two-dimensional XXZ-Ising model on a square-hexagon denoted for simplicity by 4–6 lattice with spin 1/2. The phase diagram at zero temperature is discussed, where five states are found, two types of ferrimagnetic ...