Related papers: Orbitally and Magnetically Induced Anisotropy in I…
A number of recent experiments exhibit electronic anisotropy in the iron pnictides, and there is a growing body of experimental evidence that its origin is related to orbital ordering in Fe d_{xz} and d_{yz} orbitals. We examine this…
A growing list of experiments show orthorhombic electronic anisotropy in the iron pnictides, in some cases at temperatures well above the spin density wave transition. These experiments include neutron scattering, resistivity and…
We attribute the structural phase transition (SPT) in the parent compounds of the iron pnictides to orbital ordering. Due to the anisotropy of the $d_{xz}$ and $d_{yz}$ orbitals in the $xy$ plane, a ferro-orbital ordering makes the…
The orbital fluctuation of the conduction electrons in the Iron-based superconductors is found to contribute significantly to the magnetic response of the system. With the use of a realistic five-band model and group theoretical analysis,…
Recent experiments on iron pnictides have uncovered a large in-plane resistivity anisotropy with a surprising result: the system conducts better in the antiferromagnetic x direction than in the ferromagnetic y direction. We address this…
We examine the magnetic phase diagram of iron pnictides using a five band model. For the intermediate values of the interaction expected to hold in the iron pnictides, we find a metallic low moment state characterized by antiparallel…
The resistivity anisotropy unveiled in the study of detwinned single crystals of the undoped 122 pnictides is here studied using the two-dimensional three-orbital Hubbard model in the mean-field approximation. Calculating the Drude weight…
We examine the optical conductivity in antiferromagnetic (AFM) iron pnictides by mean-field calculation in a five-band Hubbard model. The calculated spectra are well consistent with the in-plane anisotropy observed in the measurements,…
Spin wave excitations and stability of the ($\pi,0$) ordered magnetic state are investigated in a minimal two-band itinerant-electron model for iron pnictides. Presence of hopping anisotropy generates a strong ferro-orbital order in the…
We investigate the in-plane anisotropy of Fe 3d orbitals occurring in a wide temperature and composition range of BaFe2(As1-xPx)2 system. By employing the angle-resolved photoemission spectroscopy, the lifting of degeneracy in dxz and dyz…
Recent finding of an {\it unusual} in-plane resistivity anisotropy in the underdoped 122-family at high temperature ($T$) suggests an orbital nematic (ON) order, posing a challenge to extant theories. The {\it sign} of the anisotropy…
The puzzling nature of magnetic and lattice phase transitions of iron pnictides is investigated via a first-principles Wannier function analysis of representative parent compound LaOFeAs. A rare ferro-orbital ordering is found to give rise…
An ordered phase showing remarkable electronic anisotropy in proximity to the superconducting phase is now a hot issue in the field of high-transition-temperature superconductivity. As in the case of copper oxides, superconductivity in iron…
We determine theoretically the effect of spin-orbit coupling on the magnetic excitation spectrum of itinerant multi-orbital systems, with specific application to iron-based superconductors. Our microscopic model includes a realistic…
In addition to unconventional high-Tc superconductivity, the iron arsenides exhibit strong magnetoelastic coupling and a notable electronic anisotropy within the a-b plane. We relate these properties by studying underdoped…
Double exchange mechanism is believed to favor transport along ferromagnetic directions, the failure of which in explaining the unusual resistivity anisotropy in iron pnictides is investigated. Several factors intrinsic to the microscopic…
We propose that the orbital angular momentum of the conduction electrons in the Iron-based superconductors is activated in their low energy physics. Using a five-band tight-binding model derived from fitting the LDA band structure, we find…
The charge and spin of the electrons in solids have been extensively exploited in electronic devices and in the development of spintronics. Another attribute of electrons - their orbital nature - is attracting growing interest for…
Correlated electron systems, particularly iron-based superconductors, are extremely sensitive to strain, which inevitably occurs in the crystal growth process. Built-in strain of this type has been proposed as a possible explanation for…
The common phase diagrams of superconducting iron pnictides show interesting material specificities in the structural and magnetic phase transitions. In some cases the two transitions are separate and second order, while in others they…