The recently discovered magnetic topological insulators (MnBi₂Te₄)(Bi₂Te₃)_n, n = 0–4, are an ideal playground to study the influence of magnetic properties on band topology, giving access to diverse quantum states in a single compound. In the low temperature-antiferromagnetic state and vanishing magnetic field, the n = 1 system is a topological insulator protected by a combination of time reversal and a translation symmetries. It has been argued that, when the antiferromagnetic phase is forced to a the fully spin polarized state by the application of an external magnetic field, this system develops Weyl cones in the conduction band, which become accessible in presence of an intrinsic electronic doping. In this work, we experimentally prove the raising of field-induced Weyl state through the detection of an intrinsic anomalous Nernst effect in a bulk single crystal of MnBi₄Te₇.

最近发现的磁拓扑绝缘体（MnBi₂Te₄)(Bi₂Te₃)< a i=9>n、n = 0–4，是研究磁性影响的理想场所在能带拓扑上，可以在单一化合物中获得不同的量子态。在低温反铁磁态和消失磁场下，n = 1系统是一个拓扑绝缘体，受到时间反转和平移对称性的保护。有人认为，当通过施加外部磁场迫使反铁磁相处于完全自旋极化状态时，该系统在导带中形成外尔锥体，在存在固有电子掺杂的情况下变得可接近。在这项工作中，我们通过检测 MnBi 块状单晶中固有的反常能斯特效应，实验证明了场诱导外尔态的升高₄ Te₇。