摘要
Realizing phase transitions via non-thermal sample manipulations is important not only for applications,but also for uncovering the underlying physics.Here,we report on the discovery of two distinct metal–insulator transitions in 1T-TaS_(2) via angle-resolved photoemission spectroscopy and in-situ rubidium deposition.At 205 K,the rubidium deposition drives a normal metal–insulator transition via filling electrons into the conduction band.While at 225 K,however,the rubidium deposition drives a bandwidth-controlled Mott transition as characterized by a rapid collapsing of Mott gap and a loss of spectral weight of the lower Hubbard band.Our result,from a doping-controlled perspective,succeeds in distinguishing the metallic,band-insulating,and Mott-insulating phases of 1T-TaS_(2),manifesting a delicate balance among the electronitineracy,interlayer-coupling and Coulomb repulsion.We also establish an effective method to tune the balance between these interactions,which is useful in seeking exotic electronic phases and designing functional phase-changing devices.
作者
王政国
姚伟良
王宇迪
信子鸣
韩婷婷
陈磊
欧仪
朱玉
蔡淙
李源
张焱
Zhengguo Wang;Weiliang Yao;Yudi Wang;Ziming Xin;Tingting Han;Lei Chen;Yi Ou;Yu Zhu;Cong Cai;Yuan Li;Yan Zhang(International Center for Quantum Materials,School of Physics,Peking University,Beijing 100871,China)
基金
Project supported by the National Natural Science Foundation of China(Grant Nos.11888101,91421107,and 11574004)
the National Key Research and Development Program of China(Grant Nos.2018YFA0305602 and 2016YFA0301003)。