Two-spinon dynamic structure factor of the one-dimensional s=1/2 Heisenberg antiferromagnet

Article

关键词: FINITE-SIZE ANALYSIS;    MAGNETIC-FIELD;    GROUND-STATE;    CHAIN;    MODEL;    EXCHANGE;    KCUF3;   

DOI  :  10.1103/PhysRevB.55.12510

来源: SCIE

【 摘 要 】

The exact expression derived by Bougourzi, Couture, and Kacir for the two-spinon contribution to the dynamic spin structure factor S(q,omega) of the one-dimensional s=1/2 Heisenberg antiferromagnet at T=0 is evaluated for direct comparison with finite-chain transition rates (N less than or equal to 28) and an approximate analytical result previously inferred from finite-N data, sum rules, and Bethe ansatz calculations. The two-spinon excitations account for 72.89% of the total intensity in S(q,omega). The singularity structure of the exact result is determined analytically and its spectral-weight distribution evaluated numerically over the entire range of the two-spinon continuum. The leading singularities of the frequency-dependent spin autocorrelation function, static spin structure factor, and q dependent susceptibility are determined via sum rules. The impact of the non-two-spinon excitations on the integrated intensity, the susceptibility, the frequency moments, and the Euclidian time representation of S(q,omega) is studied on the basis of finite-size data.

【 授权许可】

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