Baidya Santu, Mallik Aabhaas Vineet, Bhattacharjee Subhro, Saha-Dasgupta Tanusri
Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8019, USA.
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560 089, India.
Phys Rev Lett. 2020 Jul 10;125(2):026401. doi: 10.1103/PhysRevLett.125.026401.
The binary intermetallic materials, M_{3}Sn_{2} (M=3d transition metal) present a new class of strongly correlated systems that naturally allows for the interplay of magnetism and metallicity. Using first principles calculations we confirm that bulk Fe_{3}Sn_{2} is a ferromagnetic metal, and show that M=Ni and Cu are paramagnetic metals with nontrivial band structures. Focusing on Fe_{3}Sn_{2} to understand the effect of enhanced correlations in an experimentally relevant atomistically thin single kagome bilayer, our ab initio results show that dimensional confinement naturally exposes the flatness of band structure associated with the bilayer kagome geometry in a resultant ferromagnetic Chern metal. We use a multistage minimal modeling of the magnetic bands progressively closer to the Fermi energy. This effectively captures the physics of the Chern metal with a nonzero anomalous Hall response over a material relevant parameter regime along with a possible superconducting instability of the spin-polarized band resulting in a topological superconductor.
二元金属间化合物M₃Sn₂（M = 3d过渡金属）呈现出一类新型的强关联体系，自然地允许磁性和金属性之间的相互作用。通过第一性原理计算，我们证实块状Fe₃Sn₂是一种铁磁金属，并表明M = Ni和Cu是具有非平凡能带结构的顺磁金属。聚焦于Fe₃Sn₂以理解在实验相关的原子级薄单卡戈梅双层中增强关联的影响，我们的从头算结果表明，维度限制自然地揭示了与双层卡戈梅几何结构相关的能带结构的平坦性，形成了一种铁磁陈金属。我们对逐渐靠近费米能的磁带来用多级最小建模。这有效地捕捉了陈金属的物理性质，在与材料相关的参数范围内具有非零反常霍尔响应，以及自旋极化带可能的超导不稳定性，从而导致拓扑超导体。
