凝聚态物理
物理
量子霍尔效应
磁场
朗道量子化
量子自旋霍尔效应
量子相变
分数量子霍尔效应
相变
领域(数学)
超导电性
量子临界点
量子力学
霍尔效应
量子反常霍尔效应
作者
Yifan Zhao,Ruoxi Zhang,Ling-Jie Zhou,Ruobing Mei,Zi-Jie Yan,Moses H. W. Chan,Chao-Xing Liu,Cui-Zu Chang
出处
期刊:arXiv: Mesoscale and Nanoscale Physics
日期:2021-09-23
摘要
The plateau-to-plateau transition in quantum Hall effect under high magnetic fields is a celebrated quantum phase transition between two topological states through either sweeping the magnetic field or tuning the carrier density. The recent realization of the quantum anomalous Hall (QAH) insulators with tunable Chern numbers introduces the channel degree of freedom to the dissipation-free chiral edge transport and makes the study of the quantum phase transition between two topological states under zero magnetic field possible. Here, we synthesized the magnetic topological insulator (TI)/TI penta-layer heterostructures with different Cr doping concentrations in the middle magnetic TI layers using molecular beam epitaxy (MBE). By performing transport measurements, we found a zero magnetic field quantum phase transition between the C = 1 and C = 2 QAH states. In tuning the transition, the Hall resistance monotonically decreases from h/e2 to h/2e2, concurrently, the longitudinal resistance exhibits a maximum at the critical point. Our results show that the ratio between the Hall resistance and the longitudinal resistance is greater than 1 at the critical point, which indicates that the original chiral edge channel from the C = 1 QAH state coexists with the dissipative bulk conduction channels. Subsequently, these bulk conduction channels appear to self-organize and form the second chiral edge channel in completing the plateau phase transition. Our study will motivate further investigations of this novel Chern number change-induced quantum phase transition and advance the development of the QAH chiral edge current-based electronic and spintronic devices.
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