Spectrum and transition rates of the XX chain analyzed via Bethe ansatz
Spectrum and transition rates of the XX chain analyzed via Bethe ansatz
复制标题
通过 Bethe ansatz 分析 XX 链的光谱和转移率
DOI:
--
复制
发表时间:
2003
期刊:
影响因子:
--
通讯作者:
K. Wiele
中科院分区:
文献类型:
--
作者:
Daniel Biegel;M. Karbach;G. Muller;K. Wiele
As part of a study that investigates the dynamics of the s=1/2 XXZ model in the planar regime |Delta|<1, we discuss the singular nature of the Bethe ansatz equations for the case Delta=0 (XX model). We identify the general structure of the Bethe ansatz solutions for the entire XX spectrum, which include states with real and complex magnon momenta. We discuss the relation between the spinon or magnon quasiparticles (Bethe ansatz) and the lattice fermions (Jordan-Wigner representation). We present determinantal expressions for transition rates of spin fluctuation operators between Bethe wave functions and reduce them to product expressions. We apply the new formulas to two-spinon transition rates for chains with up to N=4096 sites.