Non-local topological magnetoelectric effect by Coulomb interaction at a topological insulator-ferromagnet interface

Abstract

The interface between a topological insulator and a ferromagnetic insulator exhibits an interesting interplay of topological Dirac electrons and magnetism. As has been shown recently, the breaking of time-reversal invariance by magnetic order generates a Chern-Simons term in the action, that in turn leads to a Berry phase and a magnetoelectric effect of topological origin. Here, we consider the system in the presence of long-range Coulomb interaction between the Dirac electrons, and find that the magnetoelectric effect of the fluctuating electric field becomes non-local. We derive a Landau-Lifshitz equation for the fluctuation-induced magnetization dynamics and the Euler-Lagrange equation of the Coulomb field by explicit one-loop calculations. Via the Coulomb interaction, divergences in the in-plane magnetization affect the magnetization dynamics over large distances in a topologically protected way.

6 pages, 25 References, 1 figure. To appear in Phys. Rev. B

References in corpus (5)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Quantized topological magnetoelectric effect of the zero-plateau quantum anomalous Hall state
• Topological magneto-electric effects in thin films of topological insulators
• Fluctuation-induced magnetization dynamics and criticality at the interface of a topological insulator with a magnetically ordered layer
• Dirac electrons and domain walls: a realization in junctions of ferromagnets and topological insulators

Cited by in corpus (7)

• Magnon-induced superconductivity in a topological insulator coupled to ferro- and antiferromagnetic insulators
• Fluctuation-induced Néel and Bloch skyrmions at topological insulator surfaces
• Finite temperature fluctuation-induced order and responses in magnetic topological insulators
• Topological magnetic dipolar interaction and non-local electric magnetization control in topological insulator heterostructures
• Topological staggered field-electric effect with bipartite magnets
• Exchange tensors, generalized RKKY interactions, and magnetization dynamics in heterostructures of ferromagnets and topological insulators
• Strong photon coupling to high-frequency antiferromagnetic magnons via topological surface states