摘要
Manipulating emergent quantum phenomena is a key issue for understanding the underlying physics and contributing to possible applications.Here we study the evolution of insulating ground states of Ta_(2)Pu_(3)Te_(5) and Ta_(2)Ni_(3)Te_(5) under in-situ surface potassium deposition via angle-resolved photoemission spectroscopy.Our results confirm the excitonic insulator character of Ta_(2)d_(3)Te_(5).Upon surface doping,the size of its global gap decreases obviously.After a deposition time of more than 7 min,the potassium atoms induce a metal-insulator phase transition and make the system recover to a normal state.In contrast,our results show that the isostructural compound Ta_(2)Ni_(3)Te_(5) is a conventional insulator.The size of its global gap decreases upon surface doping,but persists positive throughout the doping process.Our results not only confirm the excitonic origin of the band gap in Ta_(2)Pd_(3)Te_(5),but also offer an effective method for designing functional quantum devices in the future.
作者
江北
姚静宇
闫大禹
郭照芃
屈歌星
邓修同
黄耀波
丁洪
石友国
王志俊
钱天
Bei Jiang;Jingyu Yao;Dayu Yan;Zhaopeng Guo;Gexing Qu;Xiutong Deng;Yaobo Huang;Hong Ding;Youguo Shi;Zhijun Wang;Tian Qian(Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China;Songshan Lake Materials Laboratory,Dongguan 523808,China;Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China;Tsung-Dao Lee Institute,New Cornerstone Science Laboratory,and School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 201210,China;Hefei National Laboratory,Hefei 230088,China)
基金
Project supported by the Ministry of Science and Technology of China (Grant No. 2022YFA1403800)
the National Natural Science Foundation of China (Grant Nos. U2032204,12188101, and U22A6005)
the Chinese Academy of Sciences (Grant No. XDB33000000)
the Synergetic Extreme Condition User Facility (SECUF)
the Center for Materials Genome。
