相关论文: Magnetic order in orbital models of the iron pnict…
In most magnetically-ordered iron pnictides, the magnetic moments lie in the FeAs planes, parallel to the modulation direction of the spin stripes. However, recent experiments in hole-doped iron pnictides have observed a reorientation of…
Spin wave excitations were measured in the ferromagnetic phase of Nd$_{1/2}$Sr$_{1/2}$MnO$_{3}$ by neutron scattering. This compound is located in proximity to the A-type antiferromagnetic state, and it shows a clear anisotropy and…
Recent experimental developments in the iron pnictides have unambiguously demonstrated the existence of in-plane electronic anisotropy in the absence of the long-range magnetic order. Such anisotropy can arise from orbital ordering, which…
We present an unbiased mean-field analysis of magnetic and charge orders in the two-dimensional Hubbard model on a square lattice, both at zero and finite temperatures. Unrestricted Hartree-Fock calculations on large finite lattices are…
The two-orbital Hubbard model for the pnictides is studied numerically using the real-space Hartree-Fock approximation on finite clusters. Upon electron doping, states with a nonuniform distribution of charge are stabilized. The observed…
Magnetic fluctuations in an unconventional superconductor (U-SC) can distinguish between distinct proposals for the symmetry of the order parameter. Motivated thereby, we undertake a study magnetic fluctuations in Iron pnictides, tracking…
We discuss the role of striction in the intertwined magnetic and structural phase transitions in the underdoped iron-pnictides. The magneto-elastic coupling to acoustic modes is then derived and estimated in framework of the multiband…
We obtain an almost complete understanding of the mean-field phase diagram of the two-dimensional Hubbard model on a square lattice with a sizable next-nearest neighbor hopping and a moderate interaction strength. In particular, we clarify…
We perform a microscopic theoretical study of the generic properties of competing magnetic phases in iron pnictides. As a function of electron filling and temperature, the magnetic stripe (single-Q) order forms a dome, but competing…
In this paper we explore the magnetic and orbital properties closely related to a tetragonal-orthorhombic structural phase transition in iron pnictides based on both two- and five-orbital Hubbard models. The electron-lattice coupling, which…
The phase diagram of iron-based superconductors contains a host of electronic orders, which are intimately connected with their superconductivity. Here we analyze the fluctuations of one type of nematic order in another. Our analysis leads…
Although the existence of nematic order in iron-based superconductors is now a well-established experimental fact, its origin remains controversial. Nematic order breaks the discrete lattice rotational symmetry by making the $x$ and $y$…
Some of the high Tc iron pnictides contain magnetic rare-earth elements, raising the question of how the existence and tunability of a d-electron antiferromagnetic order influences the heavy fermion behavior of the f-moments. With CeOFeP…
Electronic nematicity is rarely observed as an isolated instability of a correlated electron system. Instead, in iron pnictides and in certain cuprates and heavy-fermion materials, nematicity is intertwined with an underlying spin-stripe or…
In the limit of perfect nesting, the physics of iron-pnictides is governed by the density wave formation at the zone-edge vector M. At high energies, various spin- (SDW), charge- (CDW), orbital/pocket- (PDW) density waves, and their linear…
Large spin systems can exhibit unconventional types of magnetic ordering different from the ferromagnetic or N\'eel-like antiferromagnetic order commonly found in spin 1/2 systems. Spin-nematic phases, for instance, do not break…
In several parent iron-pnictide compounds the resistivity has an extended range of linear magnetic field dependence. We argue that there is a simple and natural explanation of this behavior. Spin density wave transition leads to…
In strongly correlated multi-orbital systems, various ordered phases appear. In particular, the orbital order in iron-based superconductors attracts much attention since it is considered to be the origin of the nematic state. In order to…
The origin of the nematic state is an important puzzle to be solved in iron pnictides. Iron superconductors are multiorbital systems and these orbitals play an important role at low energy. The singular $C_4$ symmetry of $d_{zx}$ and…
In this paper, we study theoretically the behaviors of the magnetic excitations(MEs) in the normal and nematic phases of iron pnictides. The normal state MEs exhibit commensurability to diamond and to square-like structure transition with…