Perspectives of the disproportionation driven superconductivity in strongly correlated 3d compounds

Abstract

Disproportionation in 3d compounds can give rise to an unconventional electron-hole Bose liquid with a very rich phase diagram from a Bose metal, charge ordering insulator to an inhomogeneous Bose superfluid. Optimal conditions for the disproportionation driven high-T_c superconductivity are shown to realize only for several Jahn-Teller d^n configurations that permit the formation of well defined local composite bosons. These are the high-spin d^4, low-spin d^7, and d^9 configurations given the octahedral crystal field, and the d^1, high-spin d^6 configurations given the tetrahedral crystal field. The disproportionation reaction has a peculiar anti-Jahn- Teller character lifting the bare orbital degeneracy. Superconductivity in the d^4 and d^6 systems at variance with d^1, d^7, and d^9 systems implies an unavoidable coexistence of the spin-triplet composite bosons and a magnetic lattice. We argue that unconventional high-T_c superconductivity observed in quasi-2D cuprates with tetragonally distorted CuO_6 octahedra and iron-based layered pnictides/chalcogenides with tetrahedrally coordinated Fe^2+ ions can be a key argument supporting the disproportionation scenario is at work in these compounds.

29 pages, 4 figures, accepted for publication in Journal of Physics:Condensed Matter

References in corpus (9)

• LiFeAs: An Intrinsic FeAs-based Superconductor with Tc = 18K
• Orbital order and possible superconductivity in LaNiO3/LaMO3 superlattices
• Field Induced Supersolid Phase in Spin-One Heisenberg Models
• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Madelung Energy of the Valence Skipping Compound BaBiO${}_3$
• Unified electronic phase diagram for hole-doped high-Tc cuprates
• Pseudogap phase in cuprates: oxygen orbital moments instead of circulating currents
• Korringa-like relaxation in the high-temperature phase of A-site ordered YBaMn2O6
• Ground state and thermal transitions in Field Induced spin-Supersolid Phase

Cited by in corpus (6)

• Effective-field theory for high-$T_c$ cuprates
• Topological structures in unconventional scenario for 2D cuprates
• Pseudo-transition between antiferromagnetic and charge orders in a minimal spin-pseudospin model of one-dimensional cuprates
• Pseudospin S=1 description of the cuprate complexity: the charge triplets model
• Insulator-bad metal transition in RNiO${}_3$ nickelates beyond Hubbard model and density functional theory
• Superconductivity in model cuprate as an S=1 pseudomagnon condensation