论文标题
自旋介导的莫特激子
Spin-Mediated Mott Excitons
论文作者
论文摘要
通过在触发物质和超电原子中的莫特绝缘子的最新实验中,我们从理论上研究了磁顺序对莫特 - 哈伯德激子的影响。特别是,我们专注于哈伯德材料中的自旋介导的双龙 - 霍隆配对。我们使用几种互补的理论技术:均值场理论来描述自由度的自旋程度,自洽的天生近似近似来表征整个哈伯德间隙的个体电荷激发,以及伯特 - 钙板方程式以识别双元和霍姆子的结合状态。发现哈伯德激子的结合能随着n {é} el阶参数的增加而增加,而激子质量降低。我们观察到这些趋势显着依赖于有效相互作用的延迟,并需要考虑改变磁性阶段的多种影响。我们的结果与最近关于触发物的实验中观察到的关键定性趋势一致。此外,这些发现可能直接含义对超低原子莫特绝缘子,其中哈伯德模型是系统的确切描述,并且可以直接访问自由度。
Motivated by recent experiments on Mott insulators, in both iridates and ultracold atoms, we theoretically study the effects of magnetic order on the Mott-Hubbard excitons. In particular, we focus on spin-mediated doublon-holon pairing in Hubbard materials. We use several complementary theoretical techniques: mean-field theory to describe the spin degrees of freedom, the self-consistent Born approximation to characterize individual charge excitations across the Hubbard gap, and the Bethe-Salpeter equation to identify bound states of doublons and holons. The binding energy of the Hubbard exciton is found to increase with increasing the N{é}el order parameter, while the exciton mass decreases. We observe that these trends rely significantly on the retardation of the effective interaction, and require consideration of multiple effects from changing the magnetic order. Our results are consistent with the key qualitative trends observed in recent experiments on iridates. Moreover, the findings could have direct implications on ultracold atom Mott insulators, where the Hubbard model is the exact description of the system and the microscopic degrees of freedom can be directly accessed.