Floquet engineering of strongly driven excitons in monolayer tungsten disulfide
Floquet engineering of strongly driven excitons in monolayer tungsten disulfide
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DOI：
10.1038/s41567-022-01849-9
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发表时间：
2022-10
期刊：
影响因子：
19.6
通讯作者：
Yuki Kobayashi;C. Heide;Amalya C. Johnson;Vishal A. Tiwari;Fang Liu;D. Reis;T. Heinz;S. Ghimire
中科院分区：
文献类型：
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作者：
Yuki Kobayashi;C. Heide;Amalya C. Johnson;Vishal A. Tiwari;Fang Liu;D. Reis;T. Heinz;S. Ghimire
量子材料与强激光场的相互作用可以诱导出奇异的非平衡电子态，-。单层过渡金属二硫属化物是一类具有显著量子限制的新型直接带隙半导体，为激子的Floquet工程提供了绝佳的机会，激子是准粒子电子-空穴关联态。强场驱动有可能实现对电子能带结构的增强控制，从而有可能打开激子光物质相互作用的新领域。然而，强场驱动激子动力学的完整表征一直是困难的。在这里，我们使用低于光学带隙的中红外激光脉冲来激发单层二硫化钨，并展示了超过一亿电子伏特的激子的强场光修整。我们的高灵敏度瞬态吸收光谱进一步揭示了在1 s激子共振以下形成的虚拟吸收特征，我们将其分配给来自暗2 p激子状态的光修饰边带。量子力学模拟证实了实验结果，使我们能够检索激子动力学的真实空间电影。这项研究推进了我们对强场区激子动力学的理解，显示了利用超快，强场现象在二维材料器件应用中的可能性。
Interactions of quantum materials with strong laser fields can induce exotic non-equilibrium electronic states, , , , –. Monolayer transition metal dichalcogenides, a new class of direct-gap semiconductors with prominent quantum confinement, offer exceptional opportunities for the Floquet engineering of excitons, which are quasiparticle electron–hole correlated states. Strong-field driving has the potential to achieve enhanced control of the electronic band structure and thus the possibility of opening a new realm of exciton light–matter interactions. However, a full characterization of strong-field driven exciton dynamics,has been difficult. Here we use mid-infrared laser pulses below the optical bandgap to excite monolayer tungsten disulfide and demonstrate strong-field light dressing of excitons in excess of a hundred millielectronvolts. Our high-sensitivity transient absorption spectroscopy further reveals the formation of a virtual absorption feature below the 1s-exciton resonance, which we assign to a light-dressed sideband from the dark 2p-exciton state. Quantum-mechanical simulations substantiate the experimental results and enable us to retrieve real-space movies of the exciton dynamics. This study advances our understanding of the exciton dynamics in the strong-field regime, showing the possibility of harnessing ultrafast, strong-field phenomena in device applications of two-dimensional materials.