Realization of Stable Ferromagnetic Order in Topological Insulator: Codoping Enhanced Magnetism in 4f Transition Metal Doped Bi2Se3

Abstract

The realization of long range and insulating ferromagnetic states in topological insulator (TI) has been a pressing issue since its discovery. Only recently, such state was achieved in Cr-doped Bi2-xSbxTe3, leading to the discovery of quantum anomalous Hall effect (QAHE). However, the effect is only observed at extremely low temperatures mainly due to the limited magnetism. To fully understand the mechanism of the ferromagnetic ordering whereby improving the ferromagnetism, we investigated 4f transition metal-doped Bi2Se3, using density-functional-theory approaches. We found that Eu and Sm prefer the Bi substitutional sites with large magnetic moments to ensure stable long-range ferromagnetic states. Additionally, codoping can be a novel strategy to preserve the insulating property of the host material as well as improving the incorporation of magnetic dopants. Our findings thus offer the critical step in facilitating the realization of QAHE in TI systems.

References in corpus (20)

• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Topological Field Theory of Time-Reversal Invariant Insulators
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Valley-Polarized Metals and Quantum Anomalous Hall Effect in Silicene
• High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
• Quantum Anomalous Hall Effect in Hg${}_{1-y}$Mn${}_y$Te Quantum Wells
• Quantum Anomalous Hall Effect in Graphene from Rashba and Exchange Effects
• Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
• Scale-Invariant Dissipationless Chiral Transport in Magnetic Topological Insulators beyond the Two-Dimensional Limit
• Quantum Anomalous Hall Effect in Graphene Proximity Coupled to an Antiferromagnetic Insulator
• Surface quantized anomalous Hall current and magneto-electric effect in magnetically disordered topological insulators
• A General Theorem Relating the Bulk Topological Number to Edge States in Two-dimensional Insulators
• Metal-to-Insulator Switching in Quantum Anomalous Hall States
• Tailoring Magnetic Doping in the Topological Insulator Bi2Se3
• Giant Anisotropic Magnetoresistance in a Quantum Anomalous Hall Insulator
• Observation of the zero Hall plateau in a quantum anomalous Hall insulator
• Chemical potential dependent gap-opening at the Dirac surface states of Bi2Se3 induced by aggregated substitutional Cr atoms
• Chern insulators from heavy atoms on magnetic substrates
• Electronic structure of (LaNiO${}_3$)${}_2$/(LaAlO${}_3$)${}_N$ heterostructures grown along [111]
• Topological phases in layered pyrochlore oxide thin films along the [111] direction

Cited by in corpus (4)

• Incipient antiferromagnetism in the Eu-doped topological insulator Bi${}_2$Te${}_3$
• Topological transitions to Weyl states in bulk Bi${}_2$Se${}_3$: Effect of hydrostatic pressure and doping
• Long Range Magnetic order stabilized by acceptors
• Carrier free long-range magnetism in Mo doped one quintuple layer Bi2Te3 and Sb2Te3