论文标题
光激发莫特绝缘子的时间分辨自旋结构因子中的反相振荡
Antiphase Oscillations in the Time-Resolved Spin Structure Factor of a Photoexcited Mott Insulator
论文作者
论文摘要
由于最近在光激发抗铁磁莫特绝缘子中的时间分辨谐振弹性X射线散射（TRRIX）的发展，我们在平方晶格上的半充满Hubbard模型中数值依赖动量的瞬态瞬态自旋动力学。关闭泵浦光子脉冲后，动态自旋结构因子的强度在时间上以频率振荡，该频率由抗铁磁莫特绝缘子中的两个镁的能量确定。我们在两个正交动量方向之间的振荡中发现了反相行为，该方向平行且垂直于泵脉冲的电场。相位差来自两麦克农激发的$ b_ {1g} $通道。观察反相振荡将是TRRIX实验的巨大挑战，当它们的时间分辨率的改善不仅仅是数量级。
Motivated by the recent development of time-resolved resonant-inelastic x-ray scattering (TRRIXS) in photoexcited antiferromagnetic Mott insulators, we numerically investigate momentum-dependent transient spin dynamics in a half-filled Hubbard model on a square lattice. After turning off a pumping photon pulse, the intensity of a dynamical spin structure factor temporally oscillates with frequencies determined by the energy of two magnons in the antiferromagnetic Mott insulator. We find an antiphase behavior in the oscillations between two orthogonal momentum directions, parallel and perpendicular to the electric field of a pump pulse. The phase difference comes from the $B_{1g}$ channel of the two-magnon excitation. Observing the antiphase oscillations will be a big challenge for TRRIXS experiments when their time resolution will be improved by more than an order of magnitude.
