The quantum anomalous Hall effect is characterized by a quantized Hall resistance with a vanishing longitudinal resistance.Many experiments reported the quantization of the Hall resistance,which is always accompanied ...The quantum anomalous Hall effect is characterized by a quantized Hall resistance with a vanishing longitudinal resistance.Many experiments reported the quantization of the Hall resistance,which is always accompanied by a non-vanishing longitudinal resistance that is several k?.Meanwhile,the non-vanishing longitudinal resistance exhibits a universal exponential decay with the increase in magnetic field.We propose that the coupling of chiral edge states,which has not been properly evaluated in the previous theories,can give rise to the non-vanishing longitudinal resistance.The coupling between the chiral edges states along the opposite boundaries can be assisted by magnetic domains or defects inside the sample bulk,which has been already identified in recent experiments.Our theory provides a potential mechanism to understand the experimental result in both magnetic topological insulator and moirésuperlattice systems.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12074108,and 12147102)Natural Science Foundation of Chongqing(Grant No.CSTB2022NSCQ-MSX0568)+4 种基金supported by the National Natural Science Foundation of China(Grant No.12074107)the Program of Outstanding Young and Middle-aged Scientific and Technological Innovation Team of Colleges and Universities in Hubei Province(Grant No.T2020001)the Innovation Group Project of the Natural Science Foundation of Hubei Province of China(Grant No.2022CFA012)supported by the Würzburg-Dresden Cluster of Excellence ct.qmat,EXC2147(Grant No.390858490)the Deutsche Forschungsgemeinschaft(Grant No.SFB 1170)。
文摘The quantum anomalous Hall effect is characterized by a quantized Hall resistance with a vanishing longitudinal resistance.Many experiments reported the quantization of the Hall resistance,which is always accompanied by a non-vanishing longitudinal resistance that is several k?.Meanwhile,the non-vanishing longitudinal resistance exhibits a universal exponential decay with the increase in magnetic field.We propose that the coupling of chiral edge states,which has not been properly evaluated in the previous theories,can give rise to the non-vanishing longitudinal resistance.The coupling between the chiral edges states along the opposite boundaries can be assisted by magnetic domains or defects inside the sample bulk,which has been already identified in recent experiments.Our theory provides a potential mechanism to understand the experimental result in both magnetic topological insulator and moirésuperlattice systems.
