论文标题
$ s> 1/2 $ Quantum Heisenberg模型的基态和动力学特性。
Ground States and Dynamical Properties of $S>1/2$ Quantum Heisenberg Model on the 1/5-Depleted Square Lattice
论文作者
论文摘要
我们研究了1/5耗尽的正方形晶格上的$ s> 1/2 $抗铁磁性海森贝格模型，这是平面耦合与平面间耦合的比率的函数。使用随机串联膨胀量子蒙特卡洛模拟，我们从数值上识别三个量子相，包括二聚体相，néel相和plaquette Valence键固相。我们还使用大规模有限尺寸缩放尺度获得了属于O（3）通用类的准确量子临界点。最重要的是，我们研究了不同阶段的动态自旋结构因子，可以通过非弹性中子散射实验来衡量。低能激发可以解释为在二聚体相和plaquette Valence键固相中的三倍。而在Néel相中，随着自旋幅度的增加，可以找到更突出的磁通模式。此外，我们在较小的$ s $上找到了更广泛的连续体，这可能是几乎脱成旋转激发的动态标志。
We study the $S>1/2$ antiferromagnetic Heisenberg model on the 1/5-depleted square lattice as a function of the ratio of the intra-plaquette coupling to the inter-plaquette coupling. Using stochastic series expansion quantum Monte Carlo simulations, we numerically identify three quantum phases, including the dimer phase, Néel phase and plaquette valence bond solid phase. We also obtain the accurate quantum critical points that belong to the O(3) universality class using the large-scale finite-size scaling. Most importantly, we study the dynamic spin structure factors of different phases, which can be measured by inelastic neutron scattering experiments. The low-energy excitations can be explained as triplons in the dimer phase and plaquette valence bond solid phase. While in the Néel phase, the more prominent magnon mode can be found as the spin magnitude increases. Furthermore, we find a broader continuum at smaller $S$, which may be the dynamical signature of nearly deconfined spinon excitations.
