Surface doping manipulation of the insulating ground states in Ta_(2)Pd_(3)Te_(5) and Ta_(2)Ni_(3)Te_(5)  

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)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Songshan Lake Materials Laboratory,Dongguan 523808,China [4]Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China [5]Tsung-Dao Lee Institute,New Cornerstone Science Laboratory,and School of Physics and Astronomy,Shanghai Jiao Tong University,Shanghai 201210,China [6]Hefei National Laboratory,Hefei 230088,China

出　　处：《Chinese Physics B》2024年第6期88-93,共6页中国物理B（英文版）

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。

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.

关 键 词：excitonic insulator metal–insulator phase transition surface doping angle-resolved photoemission spectroscopy 

分 类 号：O469[理学—凝聚态物理]