论文标题
超快谷选择性相干光学操纵与激子中的wse $ _2 $和mos $ _2 $单层
Ultrafast valley-selective coherent optical manipulation with excitons in WSe$_2$ and MoS$_2$ monolayers
论文作者
论文摘要
提高常规电子设备的速度极限需要创新的方法来操纵电子的其他量子性能。另一种方法利用了低维半导体的山谷自由度。在这里，我们证明了过渡金属二甲基元素单层中激子能量的谷化元素通过对应于几十秒秒的时间尺度上的相干光学相互作用来解除。强烈的非共振圆形光线产生的光学Stark和Bloch-siegert效应会诱导山谷选择性的激子量子水平超过30 meV。我们通过研究转交型金属二甲元中元素单层中的两个最密集的激子共振，并将结果与理论模型进行比较，该模型适当地包括库仑相互作用和激子分散体。这些结果为在Multiterahertz频率上工作的Ultrafast Valleytronics打开了大门。
Increasing the speed limits of conventional electronics requires innovative approaches to manipulate other quantum properties of electrons besides their charge. An alternative approach utilizes the valley degree of freedom in low-dimensional semiconductors. Here we demonstrate that the valley degeneracy of exciton energies in transition metal dichalcogenide monolayers may be lifted by coherent optical interactions on timescales corresponding to few tens of femtoseconds. The optical Stark and Bloch-Siegert effects generated by strong nonresonant circularly-polarized light induce valley-selective blue shifts of exciton quantum levels by more than 30 meV. We show these phenomena by studying the two most intensive exciton resonances in transiton metal dichalcogenide monolayers and compare the results to a theoretical model, which properly includes the Coulomb interaction and exciton dispersion. These results open the door for ultrafast valleytronics working at multiterahertz frequencies.
