Switching of K-Q intervalley trions fine structure and their dynamics in n-doped monolayer WS_(2)  

作　　者：Jiajie Pei Xue Liu Andrés Granados delÁguila Di Bao Sheng Liu Mohamed-Raouf Amara Weijie Zhao Feng Zhang Congya You Yongzhe Zhang Kenji Watanabe Takashi Taniguchi Han Zhang Qihua Xiong 

机构地区：[1]Collaborative Innovation Center for Optoelectronic Science and Technology,International Collaborative Laboratory of 2D Materials for Optoelectronic Science and Technology of Ministry of Education and Guangdong Province,College of Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China [2]College of Materials Science and Engineering,Fuzhou University,Fuzhou 350108,China [3]Division of Physics and Applied Physics,School of Physical and Mathematical Sciences,Nanyang Technological University,Singapore 637371,Singapore [4]College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China [5]Research Center for Functional Materials,International Center for Materials Nanoarchitectonics,National Institute for Materials Science,Tsukuba,Ibaraki 305-0044,Japan [6]State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China.

出　　处：《Opto-Electronic Advances》2023年第4期28-37,共10页光电进展（英文）

基　　金：the strong support from Singapore Ministry of Education via AcRF Tier 3 Programme “Geometrical Quantum Materials” (MOE2018-T3-1-002);AcRF Tier 2 grants (MOE2017-T2-1040);the National Natural Science Foundation of China (Grant No. 61435010);the National Natural Science Foundation of China (Grant No. 61905156);the National Natural Science Foundation of China (Grant No. 61575010);the China Postdoctoral Science Foundation (Grant No. 2017M622764);the Natural Science Foundation of Fujian Province (Grant No. 2022J01555);the Beijing Municipal Natural Science Foundation (Grant No. 4162016);the financial support of the Presidential Postdoctoral Fellowship program of the Nanyang Technological University;support from the Elemental Strategy Initiative conducted by the MEXT, Japan and the CREST (JPMJCR15F3), JST

摘　　要：Monolayer group VI transition metal dichalcogenides(TMDs)have recently emerged as promising candidates for photonic and opto-valleytronic applications.The optoelectronic properties of these atomically-thin semiconducting crystals are strongly governed by the tightly bound electron-hole pairs such as excitons and trions(charged excitons).The anomalous spin and valley configurations at the conduction band edges in monolayer WS_(2)give rise to even more fascinating valley many-body complexes.Here we find that the indirect Q valley in the first Brillouin zone of monolayer WS_(2)plays a critical role in the formation of a new excitonic state,which has not been well studied.By employing a high-quality h-BN encapsulated WS_(2)field-effect transistor,we are able to switch the electron concentration within K-Q valleys at conduction band edges.Consequently,a distinct emission feature could be excited at the high electron doping region.Such feature has a competing population with the K valley trion,and experiences nonlinear power-law response and lifetime dynamics under doping.Our findings open up a new avenue for the study of valley many-body physics and quantum optics in semiconducting 2D materials,as well as provide a promising way of valley manipulation for next-generation entangled photonic devices.

关 键 词：2D materials WS_(2) charged excitons TRIONS indirect Q-valley valleytronics 

分 类 号：TN386[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]