论文标题
相对论莫特绝缘子中的超快动态
Ultrafast dynamics in relativistic Mott insulators
论文作者
论文摘要
我们研究了相对论莫特绝缘子中的光诱导的超快动力学，即具有强旋轨耦合的莫特绝缘子。为此，我们将最小的一频哈伯德模型在带有正方形和三角形对称性的晶格上，与分层过渡金属化合物（例如sr $ _2 $ _2 $ iro $ _4 $）相关。根据晶格和旋转轨道耦合，系统倾斜了抗铁磁或$ 120^\ Circ $订单。通过模拟短激光脉冲，它们会激发它们，并使用非平衡动力学平均场理论求解动力学。脉冲产生热载体，随后由于集体阶和光载体之间的耦合而扰动磁性阶。我们发现，这种动力学形成了常规的抗铁磁体，它敏感地取决于自旋轨道耦合的空间结构。特别是在三角晶格上，放松时间受到手性$ 120^\ circ $顺序的自旋轨道耦合的影响，而在带有倾斜的抗抗铁磁序的正方形晶格上，激发后旋转式抗轨道诱导的倾斜角度保持不变。我们的研究开辟了控制磁性和超快时间尺度上的外来旋转状态的新可能性。
We study the photoinduced ultrafast dynamics in relativistic Mott insulators, i.e., Mott insulators with strong spin-orbit coupling. For this purpose, we consider a minimal one-band Hubbard model on lattices with square and triangular symmetries, as relevant for layered transition metal compounds such as Sr$_2$IrO$_4$. Depending on the lattice and the spin-orbit coupling, the systems have canted antiferromagnetic or $120^\circ$ order. They are excited by simulating a short laser pulse, and the dynamics is solved using nonequilibrium dynamical mean-field theory. The pulse generates hot carriers, which subsequently perturb the magnetic order due to the coupling between the collective order and photocarriers. We find that this dynamics, which is known form regular antiferromagnets, depends sensitively on the spatial structure of the spin-orbit coupling. On the triangular lattice, in particular, relaxation times are influenced by the spin-orbit coupling for the chiral $120^\circ$ order, while on the square lattice with canted antiferromagnetic order the spin-orbit induced canting angle remains unchanged after the excitation. Our study opens up new possibilities of controlling magnetism and exotic spin states on the ultrafast timescales.
