S(K) FOR HALDANE-GAP ANTIFERROMAGNETS - LARGE-SCALE NUMERICAL RESULTS VERSUS FIELD-THEORY AND EXPERIMENT

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关键词: ONE-DIMENSIONAL ANTIFERROMAGNETS;    SPIN-CORRELATION-FUNCTION;    GROUND-STATE PROPERTIES;    MONTE-CARLO CALCULATION;    QUANTUM ENERGY-GAP;    HEISENBERG CHAIN;    BOSE-CONDENSATION;    EXCITATIONS;    ANISOTROPY;    MODEL;   

DOI  :  10.1103/PhysRevB.49.13235

来源: SCIE

【 摘 要 】

The structure function S(k) for the s = 1, Haldane-gap antiferromagnetic chain is measured accurately using the recent density-matrix renormalization-group method, with a chain length of 100. Excellent agreement with the nonlinear-sigma-model prediction is obtained, both at k almost-equal-to pi, where a single-magnon process dominates, and at k almost-equal-to 0, where a two-magnon process dominates. We repeat our calculation with crystal-field anisotropy chosen to model Ni(C2H8N2)2NO2(ClO4), obtaining good agreement with both field-theory predictions and recent experiments. Correlation lengths, gaps, and velocities are determined for both polarizations.

【 授权许可】

Free