Dirac electrons and domain walls: a realization in junctions of ferromagnets and topological insulators

Abstract

We study a system of Dirac electrons with finite density of charge carriers coupled to an external electromagnetic field in two spatial dimensions, with a domain wall (DW) mass term. The interface between a thin-film ferromagnet and a three-dimensional topological insulator provides a condensed-matter realization of this model, when an out-of-plane domain wall magnetization is coupled to the TI surface states. We show how, for films with very weak intrinsic in-plane anisotropies, the torque generated by the edge electronic current flowing along the DW competes with an effective in-plane anisotropy energy, induced by quantum fluctuations of the chiral electrons bound to the wall, in a mission to drive the internal angle of the DW from a Bloch configuration towards a Néel configuration. Both the edge current and the induced anisotropy contribute to stabilize the internal angle, so that for weak intrinsic in-plane anisotropies DW motion is still possible without suffering from an extremely early Walker breakdown.

18 pages, 3 figures

References in corpus (7)

• Electric Field Effect in Atomically Thin Carbon Films
• The electronic properties of graphene
• Microscopic approach to current-driven domain wall dynamics
• Magnon-Driven Domain-Wall Motion with the Dzyaloshinskii-Moriya Interaction
• Spin and Orbital Magnetic Response on the Surface of a Topological Insulator
• Dynamical current-current susceptibility of gapped graphene
• Fluctuation-induced magnetization dynamics and criticality at the interface of a topological insulator with a magnetically ordered layer

Cited by in corpus (16)

• Mixed topological semimetals driven by orbital complexity in two-dimensional ferromagnets
• Chirality-dependent transmission of spin waves through domain walls
• Universal charge and current on magnetic domain walls in Weyl semimetals
• Magnon-induced superconductivity in a topological insulator coupled to ferro- and antiferromagnetic insulators
• Domain Wall in a Quantum Anomalous Hall Insulator as a Magnetoelectric Piston
• Electric manipulation of domain walls in magnetic Weyl semimetals via the axial anomaly
• Axial anomaly generation by domain wall motion in Weyl semimetals
• Non-local topological magnetoelectric effect by Coulomb interaction at a topological insulator-ferromagnet interface
• Experimental demonstration of a magnetically induced warping transition in a topological insulator mediated by rare-earth surface dopants
• Graphene with Rashba spin-orbit interaction and coupling to a magnetic layer: Electron states localized at the domain wall
• Chiral Hall effect in the kink states in topological insulators with magnetic domain walls
• Topological magnetic dipolar interaction and non-local electric magnetization control in topological insulator heterostructures
• Spin-torque resonance due to diffusive dynamics at a surface of topological insulator
• Topological staggered field-electric effect with bipartite magnets
• Probing domain wall dynamics in magnetic Weyl semimetals via the non-linear anomalous Hall effect
• Chiral electronic network within skyrmionic lattice on topological insulator surfaces