论文标题
一维莫特绝缘子的非平衡光学响应
Nonequilibrium optical response of a one-dimensional Mott insulator
论文作者
论文摘要
我们使用时间依赖性密度矩阵重新分配组方法，在施加泵脉冲后半填充时，在半填充时定义，计算和分析了一维延长哈伯德模型的非平衡差分光电导率。莫特绝缘子的熔化伴随着局部磁矩的抑制，并随之而来的是双龙对的光生成。差异光导率显示了与平均孔隙式光学状态相关的$（i）$中间隙状态，以及$（ii）$强烈的重生和杂交的兴奋性共振和吸收频段，从而产生了FANO共振。我们提供证据并将这种共振解释为类似于激发弦，（BI）激子和未结合的doublon-holon对的非平衡光学激发的签名，具体取决于现场库仑库布的大小。我们在有机Mott绝缘子的泵和探针光谱实验的背景下讨论了我们的结果。
We define, compute and analyze the nonequilibrium differential optical conductivity of the one-dimensional extended Hubbard model at half-filling after applying a pump pulse, using the time-dependent density matrix renormalization group method. The melting of the Mott insulator is accompanied by a suppression of the local magnetic moment and ensuing photogeneration of doublon-holon pairs. The differential optical conductivity reveals $(i)$ mid-gap states related to parity-forbidden optical states, and $(ii)$ strong renormalization and hybridization of the excitonic resonance and the absorption band, yielding a Fano resonance. We offer evidence and interpret such a resonance as a signature of nonequilibrium optical excitations resembling excitonic strings, (bi)excitons, and unbound doublon-holon pairs, depending on the magnitude of the intersite Coulomb repulsion. We discuss our results in the context of pump and probe spectroscopy experiments on organic Mott insulators.
