Sign competing sources of Berry curvature and anomalous Hall conductance humps in topological ferromagnets

Abstract

The use of Berry-phase concepts has established a strong link between the anomalous Hall effect (AHE) and the topological character of the Hall currents. However, the occurrence of sign competition in the Berry curvature often hinders the topological origin of the observed anomalous Hall effects. Here, we study a two-dimensional topological ferromagnet with coupled spin and orbital degrees of freedom to assess the anomalous Hall effects in the presence of sign-competing sources of Berry curvature. We show that 2D itinerant topological ferromagnets described by t2g electronic states can generally lead to topological metallic bands marked by a non-zero Chern number. We find that the resulting Berry curvature at the Fermi level exhibits a characteristic anisotropic profile with a non-monotonous angular dependence when the magnetization is reversed. The sign change of the intrinsic contribution to the anomalous Hall conductance can occur together with topological transitions or be driven by the population imbalance of the topological bands. The breaking of the inversion symmetry introduces the orbital Rashba coupling in the system. The interplay between the orbital Rashba and sign competing sources of Berry curvature leads to anomalies in the anomalous Hall conductance at values of magnetic fields for which the magnetization switches its orientation. The humps in topological ferromagnets arise when the anomalous Hall conductivity is small in absolute value and they can be detected only close to the sign-change of the AHE and far from half-filling. This study could be relevant for the family of the topological 2D ferromagnets as well as Weyl ferromagnets, and can particularly account for the variety of unconventional behaviors observed in ultrathin films of SrRuO${}_3$.

10 pages, 7 figures

References in corpus (23)

• Interface-driven topological Hall effect in SrRuO${}_3$-SrIrO${}_3$ bilayer
• Electric-field control of anomalous and topological Hall effects in oxide bilayer thin films
• Oxide spin-orbitronics: spin-charge interconversion and topological spin textures
• Quantum transport evidence of Weyl fermions in an epitaxial ferromagnetic oxide
• SU(3) Spin-Orbit Coupling in Systems of Ultracold Atoms
• Berry Curvature and Quantum Metric in $N$-band systems -- an Eigenprojector Approach
• Designing spin and orbital sources of Berry curvature at oxide interfaces
• Strain-tunable Berry curvature in quasi-two-dimensional chromium telluride
• Versatile tuning of Kerr soliton microcombs in crystalline microresonators
• Distinguishing two-component anomalous Hall effect from topological Hall effect
• Sign change of the anomalous Hall effect and the anomalous Nernst effect in Weyl semimetal CeAlSi
• Staggered Dzyaloshinskii-Moriya inducing weak ferromagnetism in centrosymmetric altermagnets and weak ferrimagnetism in noncentrosymmetric altermagnets
• Coupling charge and topological reconstructions at polar oxide interfaces
• Materials challenges for SrRuO3: from conventional to quantum electronics
• Coupling lattice instabilities across the interface in ultrathin oxide heterostructures
• Correlated Quantum Phenomena of Spin-Orbit Coupled Perovskite Oxide Heterostructures: Cases of SrRuO3 and SrIrO3-Based Artificial Superlattices
• Lecture Notes on Berry Phases and Topology
• Orbital design of Berry curvature: pinch points and giant dipoles induced by crystal fields
• Collective topological spin dynamics in a correlated spin glass
• Angular dependence of Hall effect and magnetoresistance in SrRuO${}_3$-SrIrO${}_3$ heterostructures
• Ferromagnetic order of ultra-thin La0.7Ba0.3MnO3 sandwiched between SrRuO3 layers
• Filtering Spin and Orbital Moment in Centrosymmetric Systems
• Bounds and anomalies of inhomogeneous anomalous Hall effects

Cited by in corpus (1)

• Staggered Dzyaloshinskii-Moriya and canting angle in centrosymmetric altermagnetic and ferromagnetic phases: influence on the anomalous Hall effect and Weyl points