Anomalous Nernst effect in the topological and magnetic material MnBi4Te7

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.

Automated summary

The recently discovered (MnBi2Te4)(Bi2Te3)(n) possess both magnetic and topological insulator properties. In the low temperature antiferromagnetic state and vanishing magnetic field, the n = 1 system is a topological insulator protected by time reversal and translation symmetries. It has been experimentally proven that when the antiferromagnetic phase transitions to a fully spin polarized state through the application of an external magnetic field, Weyl cones are formed in the conduction band of this system, which is accessible through intrinsic electronic doping.