相关论文: Magnetic order in orbital models of the iron pnict…

In this paper, instabilities of the isotropic metallic phase in iron pnictides are investigated. The relevant quartic fermionic interaction terms in the model are identified using phase space arguments. Using the functional integral…

Orbital-ordering instability arising due to the intrapocket nesting is investigated for the tight-binding models of pnictides in the presence of orbital-lattice coupling. The incommensurate instabilities with small momentum, which may play…

We use the results of first-principles electronic structure calculations and a strong coupling perturbation approach, together with general theoretical arguments, to illustrate the differences in super-exchange interactions between the…

The nature of the interplay between superconductivity and magnetism in the cuprates remains one of the fundamental unsolved problems in high temperature superconductivity. Whether and how these two phenomena are interdependent is perhaps…

Nematic order often breaks the tetragonal symmetry of iron-based superconductors. It arises from regular structural transition or electronic instability in the normal phase. Here, we report the observation of a nematic superconducting…

We report that special care is needed when longitudinal magnetic susceptibility is computed in a magnetically ordered phase, especially in metals. We demonstrate this by studying static susceptibility in both a ferromagnetic and an…

In the newly discovered iron-based superconductors, many experiments have demonstrated the existence of the rotational symmetry breaking nematic order, which has been a prevailing phenomenon in many correlated electronic systems. In this…

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…

We investigate how emergent nematic order and nematic fluctuations affect several macroscopic properties of both the normal and superconducting states of the iron pnictides. Due to its magnetic origin, long-range nematic order enhances…

We present a general study of the magnetic excitations within a weak-coupling five-orbital model relevant to itinerant iron pnictides. As a function of enhanced electronic correlations, the spin excitations in the symmetry broken…

We analyze spin density wave (SDW) order in iron-based superconductors and electronic structure in the SDW phase. We consider an itinerant model for Fe-pnictides with two hole bands centered at $(0,0)$ and two electron bands centered at…

Normal state spin dynamics of the recently discovered iron-pnictide superconductors is discussed by calculating spin structure factor S(q, omega) in an itinerant five-band model within RPA approximation. Due to the characteristic Fermi…

We investigated the form of the orbital ordering in the electronic nematic phase of the Iron-based superconductors by applying a group theoretical analysis on a realistic five-band model. We find the orbital order can be either of the…

We examine electronic states of antiferromagnetic phase in iron pnictides by mean-field calculations of the optical conductivity. We find that a five-band model exhibiting a small magnetic moment, inconsistent with the first-principles…

The recent discovery of superconductivity in the iron-based layered pnictides with T_c ranging between 26 and 56K generated enormous interest in the physics of these materials. Here, we review some of the peculiarities of the…

Nematic order resulting from the partial melting of density-waves has been proposed as the mechanism to explain nematicity in iron-based superconductors. An outstanding question, however, is whether the microscopic electronic model for…

It has been shown experimentally a long time ago that the magnetic ordering causes an anomalous behavior of the electron resistivity in ferromagnetic crystals. Phenomenological explanations based on the interaction between itinerant…

We consider phase transitions and potential co-existence of spin-density-wave (SDW) magnetic order and extended s-wave ($s^+$) superconducting order within a two-band itinerant model of iron pnictides, in which SDW magnetism and $s^+$…

Using linear-response density-functional theory, we obtain the magnetic interactions in the several iron pnictides. The ground state has been found to be non-collinear in FeSe, with a large continuum of nearly degenerate states lying very…

A three-orbital itinerant-electron model involving d_{xz}, d_{yz} and d_{xy} Fe 3d orbitals is proposed for iron pnictides towards understanding the (\pi,0) ordered magnetism and magnetic excitations in these materials. It is shown that…