Quantum anomalous Hall effect in intrinsic magnetic topological insulator MnBi2Te4
Quantum anomalous Hall effect in intrinsic magnetic topological insulator MnBi2Te4
复制标题
本征磁拓扑绝缘体MnBi2Te4中的量子反常霍尔效应
DOI：
10.1126/science.aax8156
复制
发表时间：
2020-02-21
期刊：
影响因子：
56.9
通讯作者：
Zhang, Yuanbo
中科院分区：
文献类型：
--
作者：
Deng, Yujun;Yu, Yijun;Zhang, Yuanbo
在磁性拓扑绝缘体中，非平凡能带拓扑与磁性有序相结合，产生奇异的物质态，如量子反常霍尔（QAH）绝缘体和轴子绝缘体。在这项工作中，我们探讨量子输运在MnBi 2 Te 4薄片-拓扑绝缘体与内禀磁序。在这种层状货车范德华晶体中，铁磁层彼此反平行耦合;然而，当样品具有奇数个七重层时，原子级薄的MnBi 2 Te 4变得铁磁。我们观察到零场QAH效应在一个五七层的标本在1.4开尔文，和外部磁场进一步提高了量子化温度为6.5开尔文通过调整所有层铁磁。结果建立MnBi 2 Te 4作为一个理想的竞技场，进一步探索各种拓扑现象的自发破缺的时间反演对称性。
In a magnetic topological insulator, nontrivial band topology combines with magnetic order to produce exotic states of matter, such as quantum anomalous Hall (QAH) insulators and axion insulators. In this work, we probe quantum transport in MnBi2Te4 thin flakes-a topological insulator with intrinsic magnetic order. In this layered van der Waals crystal, the ferromagnetic layers couple antiparallel to each other; atomically thin MnBi2Te4, however, becomes ferromagnetic when the sample has an odd number of septuple layers. We observe a zero-field QAH effect in a five-septuple-layer specimen at 1.4 kelvin, and an external magnetic field further raises the quantization temperature to 6.5 kelvin by aligning all layers ferromagnetically. The results establish MnBi2Te4 as an ideal arena for further exploring various topological phenomena with a spontaneously broken time-reversal symmetry.