论文标题
Spin-1/2中的多种木元素模式Heisenberg Antiferromagnet在强磁场中的简单正方形晶格上
Multiple magnon modes in spin-1/2 Heisenberg antiferromagnet on simple square lattice in strong magnetic field
论文作者
论文摘要
我们使用最近提出的债券运营商技术讨论Spin-$ \ frac12 $ Heisenberg Antiferromagnet磁场$ H $的简单平方晶格$ H $。众所周知，量子磁体的磁性阶段至少通过传统的自旋波理论在定性上很好地描述，该理论仅将量子校正引入问题的经典解中。我们观察到，量子波动在$ h $接近其饱和值的考虑模型的急剧动态特性上发生了巨大的动态特性：动态结构因子显示与Green的功能极点相对应的异常，该功能极点在自旋波理论中没有对应物。也就是说，量子波动会产生多个短波长的镁模式，而不会在质量上改变长波长自旋动力学。我们的结果与以前的量子蒙特卡洛模拟和有限簇的对角线化一致。
We discuss spin-$\frac12$ Heisenberg antiferromagnet on simple square lattice in magnetic field $H$ using recently proposed bond-operator technique. It is well known that magnetically ordered phases of quantum magnets are well described at least qualitatively by the conventional spin-wave theory that only introduces quantum corrections into the classical solution of the problem. We observe that quantum fluctuations change drastically dynamical properties of the considered model at $H$ close to its saturation value: the dynamical structure factor shows anomalies corresponding to Green's function poles which have no counterparts in the spin-wave theory. That is, quantum fluctuations produce multiple short-wavelength magnon modes not changing qualitatively the long-wavelength spin dynamics. Our results are in agreement with previous quantum Monte-Carlo simulations and exact diagonalization of finite clusters.
