Demonstration of robust quantum anomalous Hall effect (QAHE) in macroscopic and 3D ferromagnetic topological insulator system
Anomalous Hall effect refers to the phenomenon of linear proportionality between the anomalous Hall resistance and its magnetic moment in a magnetic system. In normal magnetic metal and semiconductor, there is no universal value for the anomalous Hall resistance. Nevertheless, in a ferromagnetic topological insulator (FM TI) under zero external magnetic field, the Dirac surface states, originating from the non-trivial bulk band topology, attain different effective masses on different surfaces. This results in a dissipationless chiral edge channel forming at the Dirac fermion mass domain-wall and gives rise to the quantization of the anomalous Hall resistance. In a recent international collaborating work led by Dr. Wei-Li Lee, Dr. Ting-Kuo Lee at IoP and Prof. K.L. Wang at UCLA USA, this effect was further demonstrated in a macroscopic and 3D FM TI. This may provide a new direction for resolving the heat dissipation problem in electronics using dissipationless chiral edge channel in a topological material. Detailed experimental results have been recently published in Physical Review Letters.
Journal Links: http://www.phys.sinica.edu.tw/index_detail.php?id=research&newsid=354
WebSite: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.137201
WebSite: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.113.137201