论文标题
室温Terahertz在单层过渡金属二进制中对激子的电吸附调制
Room Temperature Terahertz Electroabsorption Modulation by Excitons in Monolayer Transition Metal Dichalcogenides
论文作者
论文摘要
单层过渡金属二分法中的非谐振激光脉冲与激发子之间的相互作用吸引了越来越多的兴趣，这是对山谷选择性相干控制激子特性的途径。在这里，我们通过揭示了强大的THZ领域对单层MOS $ _2 $的激发共振的影响，扩展了已知的非恢复现象的分类。我们观察到，THZ泵脉冲会导致对激子的相干寿命的选择性修饰，同时保持其振荡器强度和峰值能量不变。从理论上讲，我们通过援引Franz-keldysh对激子共振的影响迄今未观察到的表现来合理化这些结果。随着光吸收的调制深度在室温下达到至0.05 dB/nm的值，我们的发现为使用半导体过渡金属二核代代构层作为高速电动吸收设备的紧凑而有效的平台开辟了道路。
The interaction between off-resonant laser pulses and excitons in monolayer transition metal dichalcogenides is attracting increasing interest as a route for the valley-selective coherent control of the exciton properties. Here, we extend the classification of the known off-resonant phenomena by unveiling the impact of a strong THz field on the excitonic resonances of monolayer MoS$_2$. We observe that the THz pump pulse causes a selective modification of the coherence lifetime of the excitons, while keeping their oscillator strength and peak energy unchanged. We rationalize these results theoretically by invoking a hitherto unobserved manifestation of the Franz-Keldysh effect on an exciton resonance. As the modulation depth of the optical absorption reaches values as large as 0.05 dB/nm at room temperature, our findings open the way to the use of semiconducting transition metal dichalcogenides as compact and efficient platforms for high-speed electroabsorption devices.
