Fluctuation-induced magnetization dynamics and criticality at the interface of a topological insulator with a magnetically ordered layer

Abstract

We consider a theory for a two-dimensional interacting conduction electron system with strong spin-orbit coupling on the interface between a topological insulator and the magnetic (ferromagnetic or antiferromagnetic) layer. For the ferromagnetic case we derive the Landau-Lifshitz equation, which features a contribution proportional to a fluctuation-induced electric field obtained by computing the topological (Chern-Simons) contribution from the vacuum polarization. We also show that fermionic quantum fluctuations reduce the critical temperature ${\tilde{T}}_c$ at the interface relative to the critical temperature $T_c$ of the bulk, so that in the interval ${\tilde{T}}_c\le T<T_c$ is possible to have coexistence of gapless Dirac fermions at the interface with a ferromagnetically ordered layer. For the case of an antiferromagnetic layer on a topological insulator substrate, we show that a second-order quantum phase transition occurs at the interface, and compute the corresponding critical exponents. In particular, we show that the electrons at the interface acquire an anomalous dimension at criticality. The critical behavior of the Néel order parameter is anisotropic and features large anomalous dimensions for both the longitudinal and transversal fluctuations.

4.5 pages, 1 figure; v2: Added some clarifications and improved presentation; references added; typos corrected; v3: Further improvements, published version

References in corpus (15)

• Topological Insulators
• Topological insulators and superconductors
• Topological Field Theory of Time-Reversal Invariant Insulators
• Universal Intrinsic Spin-Hall Effect
• Dissipationless Quantum Spin Current at Room Temperature
• Interactions and phase transitions on graphene's honeycomb lattice
• Inverse Spin-Galvanic Effect in a Topological-Insulator/Ferromagnet Interface
• SU(2) Non-Abelian Holonomy and Dissipationless Spin Current in Semiconductors
• Quantum critical scaling in graphene
• Tolerance of topological surface states towards magnetic moments: Fe on Bi2Te3 and Bi2Se3
• Orbital magnetoelectric coupling in band insulators
• Dynamics of magnetization on the topological surface
• Electric charging of magnetic textures on the surface of a topological insulator
• Witten effect in a crystalline topological insulator
• Electronic Structure Calculations of Magnetic Exchange Interactions in Europium Monochalcogenides

Cited by in corpus (17)

• Spin and Orbital Magnetic Response on the Surface of a Topological Insulator
• Spin diffusion and magnetoresistance in ferromagnet/topological-insulator junctions
• Dirac electrons and domain walls: a realization in junctions of ferromagnets and topological insulators
• Elucidating proximity magnetism through polarized neutron reflectometry and machine learning
• Temperature and Chemical Potential Dependence of the Parity Anomaly in Quantum Anomalous Hall Insulators
• Electric manipulation of domain walls in magnetic Weyl semimetals via the axial anomaly
• Topological spin-plasma waves
• Fluctuation-induced Néel and Bloch skyrmions at topological insulator surfaces
• Semi-metal-insulator transition on the surface of a topological insulator with in-plane magnetization
• Non-local topological magnetoelectric effect by Coulomb interaction at a topological insulator-ferromagnet interface
• Finite temperature fluctuation-induced order and responses in magnetic topological insulators
• Thermal screening at finite chemical potential on a topological surface and its interplay with proximity-induced ferromagnetism
• Topological magnetic dipolar interaction and non-local electric magnetization control in topological insulator heterostructures
• Nonlinear chiral photocurrent in parity-violating magnetic Weyl semimetals
• Exchange and collective behavior of magnetic impurities in a disordered helical metal
• Topological staggered field-electric effect with bipartite magnets
• Probing domain wall dynamics in magnetic Weyl semimetals via the non-linear anomalous Hall effect