Orbital mixing and strong Hund's coupling stabilize spin order in van der Waals ferromagnet CrI3

Abstract

Recent years have seen a vast increase in research into van der Waals magnetic materials. In many of these systems, magnetism is introduced via light 3d-transition metal elements, combined with chalcogenides or halogens. Despite the high technological promise in the field of spintronics, the connection between the d-orbital configuration and the occurrence of low-dimensional magnetic order is currently unclear. Here we address the prototypical two-dimensional ferromagnet CrI3, via complementary spectroscopies and density functional theory calculations. We reveal the electronic structure and orbital character of bulk CrI3 in the paramagnetic and ferromagnetic phases, describing the couplings underpinning its energy diagram, and providing a robust experimental demonstration that the stabilization of ferromagnetism is attributable to orbital mixing between I p and Cr eg states, and to the presence of strong Hund's coupling. These findings reveal the microscopic connection between orbital and spin degrees of freedom, providing fundamental insights into the behavior of low-dimensional magnetic materials.

References in corpus (31)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Layer-dependent Ferromagnetism in a van der Waals Crystal down to the Monolayer Limit
• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Magnetic 2D materials and heterostructures
• Electrical Control of 2D Magnetism in Bilayer CrI3
• Controlling magnetism in 2D CrI3 by electrostatic doping
• Electric-field switching of two-dimensional van der Waals magnets
• Strain-tunable magnetic anisotropy in monolayer CrCl${}_3$, CrBr${}_3$, and CrI${}_3$
• Intrinsic Spin and Orbital Hall Effects from Orbital Texture
• icet - A Python library for constructing and sampling alloy cluster expansions
• Magnetic Two-Dimensional Chromium Trihalides: A Theoretical Perspective
• Microscopic mechanism for higher-spin Kitaev model
• Three-dimensional magnetic critical behavior in CrI${}_3$
• Time- and angle-resolved photoemission spectroscopy of solids in the extreme ultraviolet at 500 kHz repetition rate
• Magnetic Anisotropy in Spin-3/2 with Heavy Ligand in Honeycomb Mott Insulators: Application to CrI${}_3$
• Observation of the polaronic character of excitons in a two-dimensional semiconducting magnet $\mathrm{Cr}{\mathrm{I}}_3$
• A quantitative comparison of time-of-flight momentum microscopes and hemispherical analyzers for time- and angle-resolved photoemission spectroscopy experiments
• Direct observation of the energy gain underpinning ferromagnetic superexchange in the electronic structure of CrGeTe${}_3$
• Magnetic polaron and antiferro-ferromagnetic transition in doped bilayer CrI${}_3$
• YBa${}_2$Cu${}_3$O${}_7$/La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$ bilayers: Interface coupling and electric transport properties
• Valence band electronic structure of the van der Waals ferromagnetic insulators: VI${}_3$ and CrI${}_3$
• Magnetic properties of bilayer VI3: Role of trigonal crystal field and electric-field tuning
• Electronic state unfolding for plane waves: energy bands, Fermi surfaces and spectral functions
• On-site and inter-site Hubbard corrections in magnetic monolayers: The case of FePS${}_3$ and CrI${}_3$
• X-ray magnetic circular dichroism and photoemission study of the diluted ferromagnetic semiconductor Zn${}_{1-x}$Cr${}_x$Te
• Superexchange and spin-orbit coupling in monolayer and bilayer chromium trihalides
• Dispersive dark excitons in van der Waals ferromagnet CrI3
• Anisotropic hybridization probed by polarization dependent x-ray absorption spectroscopy in VI3 van der Waals Mott ferromagnet
• Orbital correlations in ultrathin films of late transition metals
• Evidence of temperature-dependent interplay between spin and orbital moment in van der Waals ferromagnet VI3