Position-space studies of the pure and dilute quantum Ising model. III. Finite-temperature extension for higher dimensions
L. S. Campana, Alvaro Caramico D’Auria, Ugo Esposito +1 more
For pt.III see ibid., vol.20, p.1841 (1987). The global real-space renormalisation group approach is applied in two and three dimensions to study the pure and diluted transverse Ising model at finite temperatures. A phase diagram in the temperature-field plane is presented for the pure quantum model on the honeycomb, triangular and square lattices in the first-order cumulant expansion. An improvement of the classical Ising fixed-point data in two and three dimensions is considered by having recourse to larger cells and the second-order cumulant expansion. The zero-temperature percolative behaviour of the bond-diluted system is recovered from the fixed-point data analysis. Some shortcomings and relations to other approaches are also discussed.
Journal of Physics C Solid State Physics•Nov 10, 1987•4 citations