Dirac Quantum Wells at Domain Walls in Antiferromagnetic Topological Insulators

Abstract

We explore the emergence of spin-polarised flat-bands at head-to-head domain walls in a recently predicted class of antiferromagnetic topological insulators hosting planar magnetisation. We show, in the framework of quantum well physics, that by tuning the width of a domain wall one can control the functional form of the bound states appearing across it. Furthermore, we demonstrate the effect that the parity of the number of layers in a multilayer sample has on the electronic dispersion. In particular, the alignment of the magnetisation vectors on the terminating surfaces of odd layer samples affords particle-hole symmetry leading to the presence of linearly dispersing topologically non-trivial states around $E=0$. By contrast, the lack of particle-hole symmetry in even layer samples results in a gapped system, with spin-polarised flat-bands appearing either side of a band gap, with characteristic energy well within terahertz energy scales. In addition to being a versatile platform for the development of spintronic devices, when many-body interactions are accounted for we predict that these flat-bands will host strong correlations capable of driving the system into novel topological phases.

References in corpus (29)

• Topological Insulators
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators in Three Dimensions
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Weyl Semimetal in a Topological Insulator Multilayer
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Crossover of Three-Dimensional Topological Insulator of Bi2Se3 to the Two-Dimensional Limit
• Prediction and observation of the first antiferromagnetic topological insulator
• Intrinsic magnetic topological insulators in van der Waals layered MnBi${}_2$Te${}_4$-family materials
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Magnetoelectric polarizability and axion electrodynamics in crystalline insulators
• Topological axion states in magnetic insulator MnBi${}_2$Te${}_4$ with the quantized magnetoelectric effect
• Experimental demonstration of the topological surface states protected by the time-reversal symmetry
• Experimental realization of an intrinsic magnetic topological insulator
• Massive Dirac fermions and spin physics in an ultrathin film of topological insulator
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• Chiral Majorana edge state in a quantum anomalous Hall insulator-superconductor structure
• Room temperature magnetization switching in topological insulator-ferromagnet heterostructures by spin-orbit torques
• Realization of the Axion Insulator State in Quantum Anomalous Hall Sandwich Heterostructures
• Topological Quantum Computation Based on Chiral Majorana Fermions
• Intrinsic magnetic topological insulator phases in the Sb doped MnBi2Te4 bulks and thin flakes
• Natural van der Waals heterostructural single crystals with both magnetic and topological properties
• Highly-ordered wide bandgap materials for quantized anomalous Hall and magnetoelectric effects
• Quantized topological magnetoelectric effect of the zero-plateau quantum anomalous Hall state
• Electric charging of magnetic textures on the surface of a topological insulator
• Pursuing High-Temperature Quantum Anomalous Hall Effect in MnBi${}_2$Te${}_4$/Sb${}_2$Te${}_3$ Heterostructures
• Domain wall induced spin-polarized flat bands in antiferromagnetic topological insulators

Cited by in corpus (1)

• Layer Zero-Line Modes in Antiferromagnetic Topological Insulators