Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to d^4 perovskites
JSON Export
{
"metadata": {
"is_last": true,
"version": 1,
"title": "Charge disproportionation and Hund's insulating behavior in a five-orbital Hubbard model applicable to d^4 perovskites",
"keywords": [
"dynamical mean-field theory",
"metal-insulator transition",
"charge disproportionation",
"MARVEL/DD5"
],
"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.",
"license": "Creative Commons Attribution 4.0 International",
"references": [
{
"url": "https://journals.aps.org/prb/abstract/10.1103/PhysRevB.104.165135",
"type": "Journal reference",
"citation": "M. E. Merkel, C. Ederer, Phys. Rev. B 104, 165135 (2021)",
"comment": "Paper where the data and plots are discussed",
"doi": "10.1103/PhysRevB.104.165135"
},
{
"url": "https://arxiv.org/abs/2107.00348",
"comment": "Preprint to the paper where the data and plots are discussed",
"citation": "M. E. Merkel, C. Ederer, arxiv 2107.00348 (2021)",
"type": "Preprint"
}
],
"doi": "10.24435/materialscloud:3s-b5",
"conceptrecid": "1059",
"publication_date": "Oct 29, 2021, 18:55:51",
"edited_by": 100,
"_oai": {
"id": "oai:materialscloud.org:1060"
},
"contributors": [
{
"affiliations": [
"Materials Theory, ETH Z\u00fcrich, 8093 Z\u00fcrich, Switzerland"
],
"email": "maximilian.merkel@mat.ethz.ch",
"familyname": "Merkel",
"givennames": "Maximilian E."
},
{
"affiliations": [
"Materials Theory, ETH Z\u00fcrich, 8093 Z\u00fcrich, Switzerland"
],
"email": "claude.ederer@mat.ethz.ch",
"familyname": "Ederer",
"givennames": "Claude"
}
],
"owner": 566,
"license_addendum": null,
"mcid": "2021.184",
"_files": [
{
"size": 3764,
"checksum": "md5:e7b45b65406066d6ab4a144204c8f828",
"description": "Description of content of tight_binding.tar.gz and pythtb_to_Hk_file.py",
"key": "README.txt"
},
{
"size": 187860311,
"checksum": "md5:eaed503a6cf92ca6343444193777b59d",
"description": "tar.gz archive with all data and scripts needed to generate TB models, run DMFT on them and post-process results",
"key": "tight_binding.tar.gz"
},
{
"size": 5157,
"checksum": "md5:de5a8c724450f6f9f8917c2df7b7393f",
"description": "Python script to generate the necessary files for the triqs H(k) converter from the pythTB model",
"key": "pythtb_to_Hk_file.py"
}
],
"id": "1060",
"status": "published"
},
"revision": 5,
"updated": "2021-10-29T16:55:51.697025+00:00",
"created": "2021-10-25T10:41:18.055052+00:00",
"id": "1060"
}