2020/11/01 by Dmitry Ovchinnikov, Xiong Huang, Zhong Lin +17
Materials Science · Physics and Astronomy · #2D Materials and Applications #Advanced Condensed Matter Physics #Antiferromagnetism #Band gap #Condensed matter physics #Insulator (electricity) #Magnet #Magnetic field #Materials science #Optoelectronics #Physics #Quantum mechanics #Spins #Topological Materials and Phenomena #Topological insulator #Topological order #Topology (electrical circuits) #cond-mat.mes-hall #cond-mat.mtrl-sci #van der Waals force
paper · pdf · doi:10.1021/acs.nanolett.0c05117
arxiv created 2020/11/01 · openalex publication_date 2021/03/12 · arxiv updated 2021/04/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
MnBi 2 Te 4, a van der Waals magnet, is an emergent platform for exploring Chern insulator physics. Its layered antiferromagnetic order was predicted to enable even–odd layer number dependent topological states. Furthermore, it becomes a Chern insulator when all spins are aligned by an applied magnetic field. However, the evolution of the bulk electronic structure as the magnetic state is continuously tuned and its dependence on layer number remains unexplored. Here, employing multimodal probes, we establish one-to-one correspondence between bulk electronic structure, magnetic state, topological order, and layer thickness in atomically thin MnBi 2 Te 4 devices. As the magnetic state is tuned through the canted magnetic phase, we observe a band crossing, i.e., the closing and reopening of the bulk band gap, corresponding to the concurrent topological phase transition in both even- and odd-layer-number devices. Our findings shed new light on the interplay between band topology and magnetic order in this newly discovered topological magnet.