Surface magnetic ordering in topological insulators with bulk magnetic dopants
arXiv:1202.1850 · doi:10.1103/PhysRevB.85.195119
Abstract
We show that a three dimensional topological insulator doped with magnetic impurities in the bulk can have a regime where the surface is magnetically ordered but the bulk is not. This is in contrast to conventional materials where bulk ordered phases are typically more robust than surface ordered phases. The difference originates from the topologically protected gapless surface states characteristic of topological insulators. We study the problem using a mean field approach in two concrete models that give the same qualitative result, with some interesting differences. Our findings could help explain recent experimental results showing the emergence of a spectral gap in the surface state of Bi2Se3 doped with Mn or Fe atoms, but with no measurable bulk magnetism.
8 pages, 6 figures
References in corpus (14)
- The electronic properties of graphene
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Quantum Spin Hall Insulator State in HgTe Quantum Wells
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- Topological Insulators with Inversion Symmetry
- Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
- Topological Field Theory of Time-Reversal Invariant Insulators
- Quantized Anomalous Hall Effect in Magnetic Topological Insulators
- Theory of ferromagnetic (III,Mn)V semiconductors
- Topological Surface States Protected From Backscattering by Chiral Spin Texture
- The development of ferromagnetism in the doped topological insulator Bi2-xMnxTe3
- Quantum spin Hall effect in a transition metal oxide Na2IrO3
- Topological Insulators on the Lieb and Perovskite Lattices
- Momentum-Resolved Landau-Level Spectroscopy of Dirac Surface State in Bi2Se3