Competing magnetic fluctuations and orders in a multiorbital model of doped SrCo${}_2$As${}_2$

Abstract

We revisit the intriguing magnetic behavior of the paradigmatic itinerant frustrated magnet $\mathrm{Sr}{\mathrm{Co}}_2{\mathrm{As}}_2$, which shows strong and competing magnetic fluctuations yet does not develop long-range magnetic order. By calculating the static spin susceptibility $\chi (\mathbf{q})$ within a realistic sixteen orbital Hubbard-Hund model, we determine the leading instability to be ferromagnetic (FM). We then explore the effect of doping and calculate the critical Hubbard interaction strength $U_c$ that is required for the development of magnetic order. We find that $U_c$ decreases under electron doping and with increasing Hund's coupling $J$, but increases rapidly under hole doping. This suggests that magnetic order could possibly emerge under electron doping but not under hole doping, which agrees with experimental findings. We map out the leading magnetic instability as a function of doping and Hund's coupling and find several antiferromagnetic phases in addition to FM. We also quantify the degree of itinerant frustration in the model and resolve the contributions of different orbitals to the magnetic susceptibility. Finally, we discuss the dynamic spin susceptibility, $\chi (\mathbf{q},\omega )$, at finite frequencies, where we recover the anisotropy of the peaks at ${\mathbf{Q}}_{\pi }=(\pi ,0)$ and $(0,\pi )$ observed by inelastic neutron scattering that is associated with the phenomenon of itinerant magnetic frustration. By comparing results between theory and experiment, we conclude that the essential experimental features of doped SrCo${}_2$As${}_2$ are well captured by a Hubbard-Hund multiorbital model if one considers a small shift of the chemical potential towards hole doping.

arXiv comment19 pages, 12 figures

References in corpus (36)

• Maximally-localized generalized Wannier functions for composite energy bands
• Maximally localized Wannier functions: Theory and applications
• WannierTools: An open-source software package for novel topological materials
• Maximally-localized Wannier functions for entangled energy bands
• Wannier90 as a community code: new features and applications
• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• High-temperature superconductivity in iron-based materials
• Strong electronic correlations from Hund's coupling
• Near-degeneracy of several pairing channels in multiorbital models for the Fe-pnictides
• Sensitivity of the superconducting state and magnetic susceptibility to key aspects of electronic structure in ferropnictides
• Renormalized behavior and proximity to a magnetic quantum critical point in BaCo${}_2$As${}_2$
• Competing orders in FeAs layers
• Crystallographic, Electronic, Thermal and Magnetic Properties of Single-Crystal SrCo2As2
• Two successive field-induced spin-flop transitions in single-crystalline CaCo${}_2$As${}_2$
• Stripe Antiferromagnetic Spin Fluctuations in SrCo${}_2$As${}_2$
• Crystal and Magnetic Structure of CaCo{1.86}As2 Studied by X-ray and Neutron Diffraction
• Physical Properties of Metallic Antiferromagnetic CaCo{1.86}As2 Single Crystals
• Pressure dependence of dynamically screened Coulomb interactions in NiO: Effective Hubbard, Hund, intershell and intersite components
• Multiorbital Spin Susceptibility in a Magnetically Ordered State - Orbital versus Excitonic Spin Density Wave Scenario
• Selectively Localized Wannier Functions
• Effective One-Dimensional Coupling in the Highly-Frustrated Square-Lattice Itinerant Magnet CaCo${}_{2-y}$As${}_2$
• Spin-Driven Nematic Instability of the Multi-Orbital Hubbard Model: Application to Iron-Based Superconductors
• Coexistence of ferromagnetic and stripe antiferromagnetic spin fluctuations in SrCo${}_2$As${}_2$
• Crystallography and Physical Properties of BaCo2As2, Ba{0.94}K{0.06}Co2As2 and Ba{0.78}K{0.22}Co2As2
• Strain-induced tuning of the electronic Coulomb interaction in 3d transition metal oxide perovskites
• Unravelling incommensurate magnetism and its emergence in iron-based superconductors
• Spin excitations in the nematic phase and the metallic stripe spin-density wave phase of iron pnictides
• Electronic structure and spin dynamics of ACo2As2 (A=Ba, Sr, Ca)
• Role of multiorbital effects in the magnetic phase diagram of iron-pnictides
• Pressure-induced collapsed-tetragonal phase in SrCo2As2
• Competing magnetic phases and itinerant magnetic frustration in SrCo${}_2$As${}_2$
• Anomalous Composition-Induced Crossover in the Magnetic Properties of the Itinerant-Electron Antiferromagnet Ca{1-x}Sr{x}Co{2-y}As{2}
• Helical magnetic ordering in Sr(Co1-xNix)2As2
• Suppression of magnetic order in CaCo${}_{1.86}$As${}_2$ with Fe substitution: Magnetization, neutron diffraction, and x-ray diffraction studies of Ca(Co${}_{1-x}$Fe${}_x$)${}_y$As${}_2$
• Antiferromagnetic Stacking of Ferromagnetic Layers and Doping Controlled Phase Competition in Ca${}_{1-x}$Sr${}_x$Co${}_{2-y}$As${}_2$

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