Magnetic and metallic state at intermediate Hubbard<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>U</mml:mi></mml:math>coupling in multiorbital models for undoped iron pnictides

Yu, Rong; Trinh, Kien; Moreo, Adriana; Daghofer, Maria; Riera, J.; Haas, Stephan; Dagotto, Elbio

doi:10.1103/physrevb.79.104510

Cited by 63 publications

(108 citation statements)

References 91 publications

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“…It is possible that the strong-coupling (π, 0) AFM state found in Ref. 54 has lower free energy for U > 4 eV, but at these coupling strengths the AFM states are insulating and hence irrelevant to the magnetic ordering in the pnictides.…”

Section: Resultsmentioning

confidence: 93%

“…A large number of different orbital tightbinding models have therefore been proposed involving between two or five of the Fe 3d orbitals, 42,43,48,51,52,54,56,59,60,64,65,[77][78][79] or also including the As 4p orbitals 45,80 and even orbitals from outside the FeAs planes. 81 Although the existence of superconductivity in these models has been extensively studied, 40,[44][45][46]48,51,53,56,60,63,64,66 the magnetic behaviour remains rather poorly understood.…”

Section: Arxiv:10071949v2 [Cond-matsupr-con] 27 May 2011mentioning

confidence: 99%

“…81 Although the existence of superconductivity in these models has been extensively studied, 40,[44][45][46]48,51,53,56,60,63,64,66 the magnetic behaviour remains rather poorly understood. The most popular approach to the appearance of AFM order in these models is to examine the ground state using a standard mean-field ansatz that allows for at most twosite magnetic unit cells; 47,50,52,54,58,59,61,64 very recently, this has been generalized to a Gutzwiller mean-field theory. 65,68 As all of the orbital models have a rather complicated electronic structure, however, it is by no means certain that such phases have the lowest free energy, i.e.…”

Section: Arxiv:10071949v2 [Cond-matsupr-con] 27 May 2011mentioning

confidence: 99%

“…40,43,48,54,59 In all the proposed models, only on-site terms are included in the interaction Hamiltonian…”

Section: Theorymentioning

confidence: 99%

“…When constructing the mean-field phase diagrams of the orbital models, we adopt the frequently-employed ansatz 54,58,59,61,64,83 B. The magnetic susceptibility…”

Section: A Mean-field Analysismentioning

confidence: 99%

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Magnetic order in orbital models of the iron pnictides

Brydon¹,

Daghofer²,

Timm³

2011

J. Phys.: Condens. Matter

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We examine the appearance of the experimentally-observed stripe spin-density-wave magnetic order in five different orbital models of the iron pnictide parent compounds. A restricted meanfield ansatz is used to determine the magnetic phase diagram of each model. Using the random phase approximation, we then check this phase diagram by evaluating the static spin susceptibility in the paramagnetic state close to the mean-field phase boundaries. The momenta for which the susceptibility is peaked indicate in an unbiased way the actual ordering vector of the nearby meanfield state. The dominant orbitally resolved contributions to the spin susceptibility are also examined to determine the origin of the magnetic instability. We find that the observed stripe magnetic order is possible in four of the models, but it is extremely sensitive to the degree of the nesting between the electron and hole Fermi pockets. In the more realistic five-orbital models, this order competes with a strong-coupling incommensurate state which appears to be controlled by details of the electronic structure below the Fermi energy. We conclude by discussing the implications of our work for the origin of the magnetic order in the pnictides.

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Section: Resultsmentioning

confidence: 93%

Section: Arxiv:10071949v2 [Cond-matsupr-con] 27 May 2011mentioning

confidence: 99%

Section: Arxiv:10071949v2 [Cond-matsupr-con] 27 May 2011mentioning

confidence: 99%

“…40,43,48,54,59 In all the proposed models, only on-site terms are included in the interaction Hamiltonian…”

Section: Theorymentioning

confidence: 99%

“…When constructing the mean-field phase diagrams of the orbital models, we adopt the frequently-employed ansatz 54,58,59,61,64,83 B. The magnetic susceptibility…”

Section: A Mean-field Analysismentioning

confidence: 99%

See 3 more Smart Citations

Magnetic order in orbital models of the iron pnictides

Brydon¹,

Daghofer²,

Timm³

2011

J. Phys.: Condens. Matter

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Spin and Charge Susceptibilities of the Two-Orbital Model within the Cluster Perturbation Theory for Fe-Based Materials

Николаев

Korshunov

2016

J Supercond Nov Magn

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Cluster perturbation theory is used to calculate band structure, spectral functions, Fermi surface, and spin and charge susceptibilities for the twoorbital model of iron pnictides with the on-site multiorbital Hubbard interactions. Susceptibilities are calculated within the approximation combining the cluster perturbation theory for the self-energy corrections and the random-phase approximation (RPA) for the vertex renormalizations. Calculations for the small values of Hubbard repulsion U ≤ 2 eV confirm that the rigid band approximation and RPA for the spin and charge susceptibilities are suitable approaches for the case of weak interactions.

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Properties of the multiorbital Hubbard models for the iron-based superconductors

et al. 2011

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A brief review of the main properties of multiorbital Hubbard models for the Fe-based superconductors is presented. The emphasis is on the results obtained by our group at the University of Tennessee and Oak Ridge National Laboratory, Tennessee, USA, but results by several other groups are also discussed. The models studied here have two, three, and five orbitals, and they are analyzed using a variety of computational and mean-field approximations. A "physical region" where the properties of the models are in qualitative agreement with neutron scattering, photoemission, and transport results is revealed. A variety of interesting open questions are briefly discussed such as: what are the dominant pairing tendencies in Hubbard models? Can pairing occur in an interorbital channel? Are nesting effects of fundamental relevance in the pnictides or approaches based on local moments are more important? What kind of magnetic states are found in the presence of iron vacancies? Can charge stripes exist in iron-based superconductors? Why is transport in the pnictides anisotropic? The discussion of results includes the description of these and other open problems in this fascinating area of research.

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Magnetic and metallic state at intermediate HubbardUcoupling in multiorbital models for undoped iron pnictides

Cited by 63 publications

References 91 publications

Magnetic order in orbital models of the iron pnictides

Magnetic order in orbital models of the iron pnictides

Spin and Charge Susceptibilities of the Two-Orbital Model within the Cluster Perturbation Theory for Fe-Based Materials

Properties of the multiorbital Hubbard models for the iron-based superconductors

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