Wang Tianmeng, Li Zhipeng, Li Yunmei, Lu Zhengguang, Miao Shengnan, Lian Zhen, Meng Yuze, Blei Mark, Taniguchi Takashi, Watanabe Kenji, Tongay Sefaattin, Smirnov Dmitry, Zhang Chuanwei, Shi Su-Fei
Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080, United States.
Nano Lett. 2020 Oct 14;20(10):7635-7641. doi: 10.1021/acs.nanolett.0c03167. Epub 2020 Sep 14.
A strong Coulomb interaction could lead to a strongly bound exciton with high-order excited states, similar to the Rydberg atom. The interaction of giant Rydberg excitons can be engineered for a correlated ordered exciton array with a Rydberg blockade, which is promising for realizing quantum simulation. Monolayer transition metal dichalcogenides, with their greatly enhanced Coulomb interaction, are an ideal platform to host the Rydberg excitons in two dimensions. Here, we employ helicity-resolved magneto-photocurrent spectroscopy to identify Rydberg exciton states up to 11s in monolayer WSe. Notably, the radius of the Rydberg exciton at 11s can be as large as 214 nm, orders of magnitude larger than the 1s exciton. The giant valley-polarized Rydberg exciton not only provides an exciting platform to study the strong exciton-exciton interaction and nonlinear exciton response but also allows the investigation of the different interplay between the Coulomb interaction and Landau quantization, tunable from a low- to high-magnetic-field limit.
强库仑相互作用可导致形成具有高阶激发态的强束缚激子，类似于里德堡原子。巨里德堡激子的相互作用可被调控以形成具有里德堡阻塞效应的关联有序激子阵列，这对于实现量子模拟很有前景。单层过渡金属二卤化物具有极大增强的库仑相互作用，是在二维空间中承载里德堡激子的理想平台。在此，我们采用螺旋度分辨磁光电流光谱法来识别单层WSe₂中高达11s的里德堡激子态。值得注意的是，11s态的里德堡激子半径可达214纳米，比1s激子大几个数量级。巨大的谷极化里德堡激子不仅为研究强激子 - 激子相互作用和非线性激子响应提供了一个令人兴奋的平台，还允许研究库仑相互作用与朗道量子化之间不同的相互作用，这种相互作用可在从低磁场到高磁场的范围内进行调节。
