Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to d^4 perovskites


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{
  "metadata": {
    "description": "We explore the transition to a charge-disproportionated insulating phase in a five-orbital cubic tight-binding model applicable to transition-metal perovskites with a formal d^4 occupation of the transition-metal cation, such as ferrates or manganites. We use dynamical mean-field theory to obtain the phase diagram as a function of the average local Coulomb repulsion U and the Hund's coupling J. The main structure of the phase diagram follows from the zero band-width (atomic) limit and represents the competition between high-spin and low-spin homogeneous and an inhomogeneous charge-disproportionated state. This results in two distinct insulating phases: the standard homogeneous Mott insulator and the inhomogeneous charge-disproportionated insulator, recently also termed Hund's insulator. We characterize the unconventional nature of this Hund's insulating state. Our results are consistent with previous studies of two- and three-orbital models applicable to isolated t2g and eg subshells, respectively, with the added complexity of the low-spin/high-spin transition. We also test the applicability of an effective two-orbital (eg-only) model with disordered S=3/2 t2g core spins. Our results show that the overall features of the phase diagram in the high-spin region are well described by this simplified two-orbital model but also that the spectral features exhibit pronounced differences compared to the full five-orbital description.", 
    "version": 1, 
    "owner": 566, 
    "title": "Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to d^4 perovskites", 
    "_oai": {
      "id": "oai:materialscloud.org:1060"
    }, 
    "contributors": [
      {
        "givennames": "Maximilian E.", 
        "familyname": "Merkel", 
        "affiliations": [
          "Materials Theory, ETH Z\u00fcrich, 8093 Z\u00fcrich, Switzerland"
        ], 
        "email": "maximilian.merkel@mat.ethz.ch"
      }, 
      {
        "givennames": "Claude", 
        "familyname": "Ederer", 
        "affiliations": [
          "Materials Theory, ETH Z\u00fcrich, 8093 Z\u00fcrich, Switzerland"
        ], 
        "email": "claude.ederer@mat.ethz.ch"
      }
    ], 
    "references": [
      {
        "type": "Journal reference", 
        "url": "https://journals.aps.org/prb/abstract/10.1103/PhysRevB.104.165135", 
        "doi": "10.1103/PhysRevB.104.165135", 
        "citation": "M. E. Merkel, C. Ederer, Phys. Rev. B 104, 165135 (2021)", 
        "comment": "Paper where the data and plots are discussed"
      }, 
      {
        "type": "Preprint", 
        "url": "https://arxiv.org/abs/2107.00348", 
        "citation": "M. E. Merkel, C. Ederer, arxiv 2107.00348 (2021)", 
        "comment": "Preprint to the paper where the data and plots are discussed"
      }
    ], 
    "is_last": true, 
    "id": "1060", 
    "edited_by": 100, 
    "keywords": [
      "dynamical mean-field theory", 
      "metal-insulator transition", 
      "charge disproportionation", 
      "MARVEL/DD5"
    ], 
    "license": "Creative Commons Attribution 4.0 International", 
    "license_addendum": null, 
    "_files": [
      {
        "description": "Description of content of tight_binding.tar.gz and pythtb_to_Hk_file.py", 
        "size": 3764, 
        "checksum": "md5:e7b45b65406066d6ab4a144204c8f828", 
        "key": "README.txt"
      }, 
      {
        "description": "tar.gz archive with all data and scripts needed to generate TB models, run DMFT on them and post-process results", 
        "size": 187860311, 
        "checksum": "md5:eaed503a6cf92ca6343444193777b59d", 
        "key": "tight_binding.tar.gz"
      }, 
      {
        "description": "Python script to generate the necessary files for the triqs H(k) converter from the pythTB model", 
        "size": 5157, 
        "checksum": "md5:de5a8c724450f6f9f8917c2df7b7393f", 
        "key": "pythtb_to_Hk_file.py"
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    ], 
    "conceptrecid": "1059", 
    "doi": "10.24435/materialscloud:3s-b5", 
    "mcid": "2021.184", 
    "publication_date": "Oct 29, 2021, 18:55:51", 
    "status": "published"
  }, 
  "revision": 5, 
  "created": "2021-10-25T10:41:18.055052+00:00", 
  "updated": "2021-10-29T16:55:51.697025+00:00", 
  "id": "1060"
}