论文标题
扩展三角晶格哈伯德模型中的磁激发，相图和按序列的订购
Magnetic excitations, phase diagram and order-by-disorder in the extended triangular-lattice Hubbard model
论文作者
论文摘要
动态结构因子是量子磁体的重要观察因子，但由于数值和理论局限性，对超越一个维度的类似Hubbard样模型进行预测仍然是一个挑战。在这项工作中，我们研究了包括下一个最新的邻居跳跃的三角晶格哈伯德模型的磁激发。从120 $^{\ circ} $和条纹磁性订单开始，我们在自洽的随机相位近似中计算磁通光谱。在条纹阶段，我们通常找到与从相应的$ J_1 $ - $ J_2 $ HEISENBERG模型中知道的经典退化性相关的意外零模式。我们将逐序机制扩展到哈伯德系统，并显示量子波动如何稳定条纹顺序。此外，挫败感引起的磁化模式的凝结使我们能够绘制与最近数值工作非常吻合的整个相图。我们讨论了与三角晶格化合物的实验的联系，以及我们的结果与所提出的手性旋转液相的关系。
The dynamical structure factor is an important observable of quantum magnets but due to numerical and theoretical limitations, it remains a challenge to make predictions for Hubbard-like models beyond one dimension. In this work, we study the magnetic excitations of the triangular lattice Hubbard model including next-nearest neighbor hopping. Starting from the 120$^{\circ}$ and stripe magnetic orders we compute the magnon spectra within a self-consistent random phase approximation. In the stripe phase, we generically find accidental zero modes related to a classical degeneracy known from the corresponding $J_1$-$J_2$ Heisenberg model. We extend the order-by-disorder mechanism to Hubbard systems and show how quantum fluctuations stabilize the stripe order. In addition, the frustration-induced condensation of magnon modes allows us to map out the entire phase diagram which is in remarkable agreement with recent numerical works. We discuss connections to experiments on triangular lattice compounds and the relation of our results to the proposed chiral spin liquid phase.
