Dresden 2006 – scientific programme
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.107: Poster
Wednesday, March 29, 2006, 14:30–18:30, P1
High-order coupled cluster method calculations for the ground-state of quasi-one-dimensional spin systems — •Ronald Zinke1, Johannes Richter1, Jörg Schulenburg2, and Damian J.J. Farnell3 — 1Institut für Theoretische Physik, Otto-von-GuerickeUniversität Magdeburg,P.O.B. 4120, 39016 Magdeburg, Germany — 2Universitätsrechenzentrum, P.O.B. 4120, 39016 Magdeburg, Germany — 3Unit Of Ophthalmology, Department of Medicine,University Clinical Departments, Daulby Street,University of Liverpool, Liverpool L69 3GA, United Kingdom
We consider ground-state properties of quasi-1-dimensional quantum Heisenberg antiferromagnets for spin quantum numbers s=1/2 and s=1. For the investigation of the ground-state long-range order we calculate the sublattice magnetization using the high order coupled cluster method. We find that for the unfrustrated spin-1/2 system an infinitesimal inter-chain coupling J⊥ is sufficient to stabilize magnetic long-range order. This result is in agreement with known results obtained by other methods. For s=1 we find that a finite inter-chain coupling is necessary to stabilize magnetic long-range order, which can be interpreted as a result of the gapped ground-state of the spin-1 chain. The estimated value for the critical inter-chain coupling is: J⊥c ≈ 0.1. Furthermore we consider a spin-1/2 system were a frustrating next-nearest neighbor in-chain coupling is included. We find for strong frustration that again a finite inter-chain coupling J⊥ is necessary to stabilize long-range order.