Semiclassical approach to electron spin resonance in quantum spin systems
Semiclassical approach to electron spin resonance in quantum spin systems
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DOI：
10.1103/physrevb.83.224417
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发表时间：
2011-02
影响因子：
3.7
通讯作者：
S. Furuya;M. Oshikawa;I. Affleck
中科院分区：
文献类型：
--
作者：
S. Furuya;M. Oshikawa;I. Affleck
基于转子模型或非线性模型，我们发展了量子自旋系统中电子自旋共振的半经典近似。用分子动力学方法研究了经典时间演化，用经典蒙特卡罗方法对随机初始条件进行了采样。虽然这个近似在二维中可能特别有效，但我们在这里将它应用于在中间温度下，在交错和均匀磁场存在下的大自旋的一维系统。我们首先通过比较S = 2链的磁化和量子蒙特卡罗结果来测试半经典近似的有效性。然后我们计算了ESR谱，发现了广泛共存的顺磁和自旋波共振。
We develop a semi-classical approximation to electron spin resonance in quantum spin systems, based on the rotor or non-linear sigma model. The classical time evolution is studied using molec- ular dynamics while random initial conditions are sampled using classical Monte Carlo methods. Although the approximation may be especially powerful in two dimensions, we apply it here to one- dimensional systems of large spin at intermediate temperatures, in the presence of staggered and uniform magnetic fields. We first test the validity of the semi-classical approximation by comparing the magnetization to quantum Monte Carlo results on S = 2 chains. Then we calculate the ESR spectrum, finding broad coexisting paramagnetic and spin wave resonances.