Wave-number-dependent susceptibilities of one-dimensional quantum spin models at zero temperature

1985 ◽  
Vol 31 (1) ◽  
pp. 637-640 ◽  
Author(s):  
Gerhard Müller ◽  
Robert E. Shrock
1987 ◽  
Vol 65 (5) ◽  
pp. 489-491 ◽  
Author(s):  
S. Fujiki

The calculation of two- and four-spin correlations of the [Formula: see text] Heisenberg antiferromagnet has been extended to an N = 21 site triangular lattice. The infinite-lattice ground state energy per bond is estimated to be E0/3NJ = −0.3678 ± 0.005 by fitting a quadratic in 1/N to the finite N data. The plaquette chirality order is slightly greater than in the XY antiferromagnet. The two-spin correlation is conjectured to decay as [Formula: see text].


1997 ◽  
Vol 56 (10) ◽  
pp. 5985-5995 ◽  
Author(s):  
D. V. Dmitriev ◽  
V. Ya. Krivnov ◽  
A. A. Ovchinnikov

1999 ◽  
Vol 77 (5) ◽  
pp. 353-369 ◽  
Author(s):  
D D Betts ◽  
H Q Lin ◽  
J S Flynn

This paper describes an improvement in the method of exact diagonalization of Hamiltonians of quantum spin models on finite square lattices and the statistical analysis of the data so obtained to estimate the physical properties of the models on the infinite square lattices at zero temperature. The geometry and topology of finite square lattices are described. The models studied are the spin one-half XY and Heisenberg antiferromagnets using 28 finite square lattices with up to 32 vertices. Our estimates of the energy and magnetization on each model on the infinite lattice at zero temperature compare very well with recent estimates using quantum Monte Carlo, series expansion, and spin wave estimates. Estimates of spin wave velocity and transverse susceptibilities are more scattered.PACS No.: 75.10J


1993 ◽  
Vol 07 (27) ◽  
pp. 1747-1759 ◽  
Author(s):  
PETER KOPIETZ

Using an analogy between the conductivity tensor of electronic systems and the spin stiffness tensor of spin systems, we introduce the concept of the Thouless number g0 and the dimensionless frequency-dependent conductance g(ω) for quantum spin models. It is shown that spin diffusion implies the vanishing of the Drude peak of g(ω), and that the spin diffusion coefficient Ds is proportional to g0. We develop a new method based the Thouless number to calculate D s , and present results for D s in the nearest-neighbor quantum Heisenberg ferromagnet at infinite temperatures for arbitrary dimension d and spin S.


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