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arXiv 2402.17416cond-mat.str-el
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铁磁 S=1 链自旋动力学的半经典方法

Semiclassical approach to spin dynamics of a ferromagnetic S=1 chain

Chengchen Li, Yi Cui, Weiqiang Yu, Rong Yu

AI总结:

本文用半经典分子动力学方法研究具有单离子各向异性的S=1铁磁海森堡链的自旋动力学,揭示了横向磁场下铁磁-顺磁量子相变,并阐明了动力学结构因子中磁振子色散、单/双磁振子连续谱及其温度依赖性,为准一维磁体的实验探测提供理论指导。

摘要:

受准一维量子磁体 NiNb$_2$O$_6$ 近期实验进展的启发,我们采用半经典分子动力学方法研究了具有单离子各向异性的 S=1 铁磁海森堡链的自旋动力学。该系统在横向磁场下经历从铁磁态到顺磁态的量子相变,反映这一相变的磁响应被我们的半经典方法很好地描述。我们表明,在低温下,动力学结构因子的横向分量清晰地描绘出磁振子色散关系,而纵向分量则展现出分别与单磁振子和双磁振子激发相关的两个连续谱。由于磁振子相互作用的影响,这些自旋激发谱表现出有趣的温度依赖性。我们的发现为准一维磁体大类中自旋激发的实验探测提供了启示。

英文摘要:

Motivated by recent experimental progress in the quasi-one-dimensional quantum magnet NiNb$_2$O$_6$, we study the spin dynamics of an S=1 ferromagnetic Heisenberg chain with single-ion anisotropy by using a semiclassical molecular dynamics approach. This system undergoes a quantum phase transition from a ferromagnetic to a paramagnetic state under a transverse magnetic field, and the magnetic responses reflecting this transition is well described by our semiclassical method. We show that at low-temperature the transverse component of the dynamical structure factor depicts clearly the magnon dispersion, and the longitudinal component exhibits two continua associated with single- and two-magnon excitations, respectively. These spin excitation spectra show interesting temperature dependence as effects of magnon interactions.Our findings shed light on experimental detection of spin excitations in a large class of quasi-one-dimensional magnets.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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