Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.101: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Coupled cluster calculation of the ground state of the J1–J2 model on the square lattice — •R. Darradi1, J. Richter1, Sven E. Krüger2, R. Zinke1, and D. J. J. Farnell3 — 1Institut für Theoretische Physik, Otto-von-Guericke Universität Magdeburg, P.O.B. 4120, 39016 Magdeburg, Germany — 2IESK Kognitive Systeme, Universität Magdeburg, PF 4120, 39016 Magdeburg, Germany — 3Unit Of Ophthalmology, Department of Medicine, University Clinical Departments, Daulby Street, University of Liverpool, Liverpool L69 3GA, United Kingdom
Using the coupled cluster method (CCM) for high orders of approximation we investigate the ground state properties of J1–J2 model on the square lattice. By calculation of the sublattice magnetization, the spin stiffness, and the spin gap we determine the quantum critical point J2c, where magnetic LRO disappears. We estimate J2c ≈ 0.4J1 which is in good agreement with the results obtained by other approximations.