Related papers: Consistent model of magnetism in ferropnictides
It is argued that the phase transition in low-T_c clean itinerant ferromagnets is generically of first order, due to correlation effects that lead to a nonanalytic term in the free energy. A tricritical point separates the line of first…
One view of the cuprate high-transition temperature (high-Tc) superconductors is that they are conventional superconductors where the pairing occurs between weakly interacting quasiparticles, which stand in one-to-one correspondence with…
The symmetry of the superconducting states arising directly from ferromagnetic states in the crystals with cubic and orthorombic symmetries is described. The symmetry nodes in the quasiparticle spectra of such the states are pointed out if…
An unusual successive phase transition from superconducting (SC) to antiferromagnetic (AF) phases was discovered via ^{75}As and ^{27}Al nuclear magnetic resonance (NMR) in (Fe_2As_2)(Ca_6(Al, Ti)_4O_y) with four (Al, Ti)O layers…
Magnetic spin fluctuations is one candidate to produce the bosonic modes that mediate the superconductivity in the ferrous superconductors. Up until now, all of the LaOFeAs and BaFe2As2 structure types have simple commensurate magnetic…
In the generic phase diagram of heavy fermion systems, tuning an external parameter such as hydrostatic or chemical pressure modifies the superconducting transition temperature. The superconducting phase forms a dome in the…
On the basis of the Hubbard model, we present the formulation of antiferromagnetism in electron-doped cuprates using the fluctuation-exchange approach. Taking into account the spin fluctuations in combination with the impurity scattering…
A hallmark of the iron-based superconductors is the strong coupling between magnetic, structural and electronic degrees of freedom. However, a universal picture of the normal state properties of these compounds has been confounded by recent…
The extreme variability of observables across the phase diagram of the cuprate high temperature superconductors has remained a profound mystery, with no convincing explanation of the superconducting dome. While much attention has been paid…
A detailed study of poly- and single crystalline samples of the normal spinel HgCr2S4 is reported. The structural refinement reveals enhanced values of the atomic displacements suggesting closeness to a structural instability.…
The description and detection of unconventional magnetic states such as spin liquids is a recurring topic in condensed matter physics. While much of the efforts have traditionally been directed at geometrically frustrated antiferromagnets,…
The magnetic properties of iron pnictide superconductors with magnetic rare-earth ions under strong magnetic field are investigated based on the cluster self-consistent field method. Starting from an effective Heisenberg model, we present…
We study whether Fermi-surface (FS) nesting can give rise to high-temperature superconductivity in iron pnictides. Starting with ab initio construction of an effective four-orbital model, we employ the fluctuation-exchange approximation to…
Two predictions are made for properties of the ferromagnetic superconductors discovered recently. The first one is that spin-triplet, p-wave pairing in such materials will give the magnons a mass inversely proportional to the square of the…
We investigate the structural, electronic, and magnetic properties of the hypothetical compound BaFePn2 (Pn = As and Sb), which is isostructural to the parent compound of the high temperature superconductor LaFeAsO1-xFx. Using density…
A microscopic mean-field theory of the phase coexistence between ferromagnetism and superconductivity in the weakly ferromagnetic itinerant electron system is constructed, while incorporating a realistic mechanism for superconducting…
The first-principles electronic structure calculations made substantial contribution to study of high $T_c$ iron-pnictide superconductors. By the calculations, LaFeAsO was first predicted to be an antiferromagnetic semimetal, and the novel…
In this work, we study a biquadratic Heisenberg model with coupled orbital degree of freedom using Monte Carlo simulation in order to investigate the phase transitions in iron-based superconductors. The antiferro-quadrupolar state, which…
Magnetic superconductors are specific materials exhibiting two antagonistic phenomena, superconductivity and magnetism, whose mutual interaction induces various emergent phenomena, such as the reentrant superconducting transition associated…
There is strong evidence that magnetic interactions play a crucial role in the mechanism driving high-temperature superconductivity in cuprate superconductors. To investigate this further we have done neutron scattering experiments on the…