Role of orbital off-diagonal spin and charge condensates in a three orbital model for Ca2RuO4 – Coulomb renormalized spin-orbit coupling, orbital moment, and tunable magnetic order

Mohapatra, Shubhajyoti; Kundu, Ritajit; Dubey, Ashutosh Kumar; Dutta, Debasis; Singh, Amreek

doi:10.1016/j.jmmm.2021.168172

Cited by 4 publications

(4 citation statements)

References 40 publications

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“…Recent application to the 3d compound Sr 2 VO 4 with n = 1 reveals an SOC induced transition from staggered orbital + ferromagnetic (FM) order to entangled orbital + AFM order at critical SOC value λ * ≈ 30 meV [35]. Generally, coupling of orbital moments to orbital fields and interaction-induced SOC renormalization effects highlight the important role of SOC induced OM condensates in the emergent spin-orbital physics [39].…”

Section: Model Hamiltonian and Generalized Self Consistent + Fluctuat...mentioning

confidence: 99%

Spin–orbit coupling and magnetism in Sr2CrO4

Mohapatra

Singh

2023

J. Phys.: Condens. Matter

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With one electron in the degenerate yz,xz orbital sector, the Sr2CrO4 compound exhibits active orbital degree of freedom, resulting in strongly enhanced orbital and spin-orbital correlations due to Coulomb interaction induced renormalization of the otherwise weak bare spin-orbit coupling (SOC) in this 3d transition metal compound. Finite temperature orbital fluctuations strongly reduce spin-orbital correlations, effective SOC strength, and magnon excitation energy. Orbital and magnetic transition temperatures estimated from the calculated orbiton and (renormalized) magnon energies are in good agreement with the experimental values obtained from susceptibility and resistivity anomalies in recent high-pressure studies.

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Section: Model Hamiltonian and Generalized Self Consistent + Fluctuat...mentioning

confidence: 99%

Spin–orbit coupling and magnetism in Sr2CrO4

Mohapatra

Singh

2023

J. Phys.: Condens. Matter

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“…We will use the generalized self-consistent approach in which all orbital diagonal and orbital mixing condensates (⟨ψ † µ σψ ν ⟩ and ⟨ψ † µ ψ ν ⟩) of the spin and charge operators are included in the HF approximation of the Coulomb interaction terms. This approach was recently applied to the NaOsO 3 , Ca 2 RuO 4 , and Sr 2 IrO 4 compounds [17,21,22], and has been extended to the chromate compound Sr 2 CrO 4 [23], where a SOC induced staggered-to-entangled orbital order transition was found in the reversed crystal field regime corresponding to ambient pressure.…”

Section: Generalized Self-consistent + Fluctuations Approachmentioning

confidence: 99%

Spin–orbit coupling, orbitally entangled antiferromagnetic order, and collective spin–orbital excitations in Sr2VO4

Mohapatra¹,

Singh²,

Ray³

et al. 2022

J. Phys.: Condens. Matter

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With electron filling $n=1$ in the $\rm Sr_2VO_4$ compound, the octahedrally coordinated $t_{\rm 2g}$ orbitals are strongly active when the tetragonal distortion induced crystal field is tuned by external agent such as pressure. Considering the full range of crystal field induced tetragonal splitting in a realistic three-orbital model, collective spin-orbital excitations are investigated using the generalised self consistent plus fluctuation approach. At ambient pressure, an entangled orbital + antiferromagnetic order is found to be stabilised beyond a critical value ($\sim$ 30 meV) of spin-orbit coupling which is in the realistic range for 3d ions. The behaviour of the calculated energy scales of collective excitations with crystal field is consistent with that of the transition temperatures with pressure as obtained from susceptibility and resistivity anomalies in high-pressure studies.

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“…The generalized self consistent approach including all orbital diagonal and off-diagonal spin and charge condensates has been applied recently to the NaOsO 3 , Ca 2 RuO 4 , and Sr 2 IrO 4 compounds, 17,21,22 illustrating the rich interplay between different physical elements. The coupling of orbital moments to weak orbital fields and the interaction-induced SOC renormalization highlight the role of orbital off-diagonal condensates on the emergent orbital and spin-orbital physics.…”

Section: Generalized Self Consistent + Fluctuation Approachmentioning

confidence: 99%

“…Although the SOC-like λ int α L α S α terms are a subset of Eq. ( 3) which explicitly preserves spin rotation symmetry, 22 effectively enhanced SOC and magnetic anisotropy effect is seen in the generalized self consistent calculation due to the Coulomb orbital mixing terms. 23 Since all generalized spin ψ † µ σψ ν and charge ψ † µ ψ ν condensates are included in the self consistent approach, the fluctuation propagator must also be defined in terms of the generalized operators.…”

Section: Generalized Self Consistent + Fluctuation Approachmentioning

confidence: 99%

Orbital entangled antiferromagnetoc order and spin-orbit-distortion exciton in $\rm Sr_2VO_4$

Mohapatra¹,

Singh²,

Ray³

et al. 2022

Preprint

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With electron filling n = 1 in the Sr 2 VO 4 compound, the octahedrally coordinated t 2g orbitals are strongly active due to tetragonal distortion induced crystal field tuning by external agent such as pressure. Considering the full range of crystal field induced tetragonal splitting in a realistic three-orbital model, collective spinorbital excitations are investigated using the generalized self consistent and fluctuation approach. The variety of self consistent states obtained including orbital entangled ferromagnetic and antiferromagnetic orders reflects the rich spin-orbital physics resulting from the interplay between the band, spin-orbit coupling, crystal field, and Coulomb interaction terms. The behavior of the calculated energy scales of collective excitations with crystal field is consistent with that of the transition temperatures with pressure as obtained from susceptibility and resistivity anomalies in high-pressure studies.

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Role of orbital off-diagonal spin and charge condensates in a three orbital model for Ca2RuO4 – Coulomb renormalized spin-orbit coupling, orbital moment, and tunable magnetic order

Cited by 4 publications

References 40 publications

Spin–orbit coupling and magnetism in Sr2CrO4

Spin–orbit coupling and magnetism in Sr2CrO4

Spin–orbit coupling, orbitally entangled antiferromagnetic order, and collective spin–orbital excitations in Sr2VO4

Orbital entangled antiferromagnetoc order and spin-orbit-distortion exciton in $\rm Sr_2VO_4$

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