Breakdown of Hund's rule for CuFeAs

  title={Breakdown of Hund's rule for CuFeAs},
  author={Zeyi Song and Xiuguang Jiang and Xiao-Fang Ouyang and Yu-Zhong Zhang},
  journal={Physical Review B},
The ground-state properties of CuFeAs were investigated by applying density functional theory calculations within the generalized gradient approximation (GGA) and $\mathrm{GGA}+U$. We find that the bicollinear antiferromagnetic state with antiparallel orbital magnetic moments on each iron which violates the Hund's rule is favored by the on-site Coulomb interaction, which is further stabilized by Cu vacancy. The magnetic ground state can be used to understand weak antiferromagnetism in CuFeAs… 

Figures from this paper



Magnetism and site exchange in CuFeAs and CuFeSb: A microscopic and theoretical investigation

We have investigated the magnetic ground state of CuFeAs and CuFeSb by means of Fe-Mössbauer spectroscopy, muon spin rotation/relaxation (μSR), neutron diffraction, and electronic structure

Orbital selectivity in Hund's metals: The iron chalcogenides

We show that electron correlations lead to a bad metallic state in chalcogenides FeSe and FeTe despite the intermediate value of the Hubbard repulsion U and Hund’s rule coupling J . The evolution of

Origin of the 150-K anomaly in LaFeAsO: competing antiferromagnetic interactions, frustration, and a structural phase transition.

  • T. Yildirim
  • Physics, Materials Science
    Physical review letters
  • 2008
From all-electron fixed-spin-moment calculations, the presence of competing strong antiferromagnetic exchange interactions suggests that magnetism and superconductivity in doped LaFeAsO may be strongly coupled, much like in the high-T(c) cuprates.

Strong correlations and magnetic frustration in the high Tc iron pnictides.

The iron pnictides are considered in terms of a proximity to a Mott insulator, and the exchange interactions favor a d-wave superconducting order parameter; in the notation appropriate for the Fe square lattice, its orbital symmetry is dxy.

Pnictide-height dependent ferromagnetism in CuFeAs and CuFeSb

Low magnetization and anisotropy in the antiferromagnetic state of undoped iron pnictides.

This work examines the magnetic phase diagram of iron pnictides using a five-band model and finds a metallic low moment state characterized by antiparallel orbital magnetic moments, which accounts for the small magnetization measured in undoped iron pNictides and leads to the strong exchange anisotropy found in neutron experiments.

Unconventional superconductivity with a sign reversal in the order parameter of LaFeAsO1-xFx.

We argue that the newly discovered superconductivity in a nearly magnetic, Fe-based layered compound is unconventional and mediated by antiferromagnetic spin fluctuations, though different from the

Electron-hole symmetry and magnetic coupling in antiferromagnetic LaFeAsO.

Calculated Fe-Fe transverse exchange couplings Jij(R) reveal that exchange coupling is strongly dependent on both the AFM symmetry and on the Fe-As distance.

Microscopic origin of magnetism and magnetic interactions in ferropnictides

One year after their initial discovery, two schools of thought have crystallized regarding the electronic structure and magnetic properties of ferropnictide systems. One postulates that these are

Coherence–incoherence crossover in the normal state of iron oxypnictides and importance of Hund's rule coupling

A new class of high-temperature superconductors based on iron and arsenic was recently discovered (Kamihara et al 2008 J. Am. Chem. Soc. 130 3296), with the superconducting transition temperature as