Strongly Gapped Topological Surface States on Protected Surfaces of Antiferromagnetic MnBi${}_4$Te${}_7$ and MnBi${}_6$Te${}_{10}$

Abstract

The search for materials to support the Quantum Anomalous Hall Effect (QAHE) have recently centered on intrinsic magnetic topological insulators (MTIs) including MnBi${}_2$Te${}_4$ or heterostructures made up of MnBi${}_2$Te${}_4$ and Bi${}_2$Te${}_3$. While MnBi${}_2$Te${}_4$ is itself a MTI, most recent ARPES experiments indicate that the surface states on this material lack the mass gap that is expected from the magnetism-induced time-reversal symmetry breaking (TRSB), with the absence of this mass gap likely due to surface magnetic disorder. Here, utilizing small-spot ARPES scanned across the surfaces of MnBi${}_4$Te${}_7$ and MnBi${}_6$Te${}_{10}$, we show the presence of large mass gaps (~ 100 meV scale) on both of these materials when the MnBi${}_2$Te${}_4$ surfaces are buried below one layer of Bi${}_2$Te${}_3$ that apparently protects the magnetic order, but not when the MnBi${}_2$Te${}_4$ surfaces are exposed at the surface or are buried below two Bi${}_2$Te${}_3$ layers. This makes both MnBi${}_4$Te${}_7$ and MnBi${}_6$Te${}_{10}$ excellent candidates for supporting the QAHE, especially if bulk devices can be fabricated with a single continuous Bi${}_2$Te${}_3$ layer at the surface.

17 pages, 4 figures

References in corpus (19)

• Maximally-localized generalized Wannier functions for composite energy bands
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Topological axion states in magnetic insulator MnBi${}_2$Te${}_4$ with the quantized magnetoelectric effect
• Quantum Anomalous Hall Effect in Hg${}_{1-y}$Mn${}_y$Te Quantum Wells
• Experimental realization of an intrinsic magnetic topological insulator
• Quantum Anomalous Hall Effect in Graphene from Rashba and Exchange Effects
• Unique thickness-dependent properties of the van der Waals interlayer antiferromagnet $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ films
• Magnetic impurities on the surface of a topological insulator
• Intrinsic magnetic topological insulator phases in the Sb doped MnBi2Te4 bulks and thin flakes
• Chemical Aspects of the Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$
• A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling
• Highly-ordered wide bandgap materials for quantized anomalous Hall and magnetoelectric effects
• Realization of an intrinsic, ferromagnetic topological state in MnBi8Te13
• Surface states and Rashba-type spin polarization in antiferromagnetic MnBi${}_2$Te${}_4$
• Rational design principles of quantum anomalous Hall effect from superlattice-like magnetic topological insulators
• Magnetic topological insulator MnBi6Te10 with zero-field ferromagnetic state and gapped Dirac surface states
• Universal gapless Dirac cone and tunable topological states in (MnBi${}_2$Te${}_4$)${}_m$(Bi${}_2$Te${}_3$)${}_n$ heterostructures

Cited by in corpus (13)

• Layer Hall effect in a 2D topological Axion antiferromagnet
• Variety of magnetic topological phases in the (MnBi${}_2$Te${}_4$)(Bi${}_2$Te${}_3$)${}_m$ family
• Magnetic topological insulator MnBi6Te10 with zero-field ferromagnetic state and gapped Dirac surface states
• Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi${}_4$Te${}_7$ and MnBi${}_6$Te${}_{10}$
• Tuning the magnetism and band topology through antisite defects in Sb doped MnBi4Te7
• Hybridization-Induced Gapped and Gapless States on the Surfaces of Magnetic Topological Insulators
• Spectroscopic realization of large surface gap in a doped magnetic topological insulator
• Light-Tunable Surface State and Hybridization Gap in Magnetic Topological Insulator MnBi${}_8$Te${}_{13}$
• Delicate Ferromagnetism in MnBi${}_6$Te${}_{10}$
• Strongly anisotropic spin dynamics in magnetic topological insulators
• Unconventional pressure-driven metamagnetic transitions in topological van der Waals magnets
• Magnetic warping in topological insulators
• Fate of surface gaps in magnetic topological insulators