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Dynamical Spin Response Functions for Heisenberg Ladders

Danny Yang·Wick Haxton
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Abstract

We present the results of a numerical study of the 2 by L spin 1/2 Heisenberg ladder. Ground state energies and the singlet-triplet energy gaps for L = (4-14) and equal rung and leg interaction strengths were obtained in a Lanczos calculation and checked against earlier calculations by Barnes et al. (even L up to 12). A related moments technique is then employed to evaluate the dynamical spin response for L=12 and a range of rung to leg interaction strength ratios (0 - 5). We comment on two issues, the need for reorthogonalization and the rate of convergence, that affect the numerical utility of the moments treatment of response functions.

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Danny Yang, Wick Haxton. 1997-12-12. Dynamical Spin Response Functions for Heisenberg Ladders. https://doi.org/10.1103/physrevb.57.10603

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