J. Phys. I France 4 (1994) 1573-1576
Spin-spin correlations in the tt'-Hubbard modelT. Husslein1, 2, D.M. Newns1, H.G. Mattutis2, P.C. Pattnaik1, I. Morgenstern1, 2, J.M. Singer2, W. Fettes2 and C. Baur2
1 IBM Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598, U.S.A.
2 Universität Regensburg, Fakultät Physik, D-93040 Regensburg, Germany
(Received 29 August 1994, received in final form 8 September 1994, accepted 13 September 1994)
We present calculations of the tt'-Hubbard model using Quantum Monte Carlo techniques. The parameters are chosen so that the van Hove Singularity in the density of states and the Fermi level coincide. We study the behaviour of the system with increasing Hubbard interaction U. Special emphasis is on the spin-spin correlation (SSC). Unusual behaviour for large U is observed there and in the momentum distribution function ( n(q)).
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