Related papers: Competing Orders and Spin-Density-Wave Instability…
In this paper we calculate the electron-phonon coupling of the newly-discovered superconductor LaO$_{1-x}$F$_x$FeAs from first-principles, using Density Functional Perturbation Theory. For pure LaOFeAs, the calculated electron-phonon…
The recent discovery of superconductivity with relatively high transition temperature Tc in the layered iron-based quaternary oxypnictides La[ O1-xFx] FeAs was a real surprise. The excitement generated can be seen by the number of…
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 $s^+$…
The nature of spin-density wave and its relation with superconductivity are crucial issues in the newly discovered Fe-based high temperature superconductors. Particularly it is unclear whether the superconducting phase and spin density wave…
Motivated by recent neutron scattering experiments, we study the ordering of spins in the iron-based superconductors La(O_{1-x}F_x)FeAs, assuming them in proximity to a Mott insulator in the phase diagram. The ground state of the parent…
We argue that superconductivity in the coexistence region with spin-density-wave (SDW) order in weakly doped Fe-pnictides differs qualitatively from the ordinary $s^{+-}$ state outside the coexistence region, as it develops an additional…
The discovery of high temperature superconductivity in La[O1-xFx]FeAs at the beginning of this year [1] has generated much excitement and has led to the rapid discovery of similar compounds with as high as 55 K transition temperatures [2].…
We study the interplay between superconductivity and spin density wave order in graphene doped to 3/8 or 5/8 filling (a Van Hove doping). At this doping level, the system is known to exhibit weak coupling instabilities to both chiral d + id…
We present the first comprehensive derivation of the intrinsic electronic phase diagram of the iron-oxypnictide superconductors in the normal state based on the analysis of the electrical resistivity $\rho$ of both LaFeAsO$_{1-x}$F$_x$ and…
In a simple model we investigate three competing orders: d-wave superconductivity, spin and orbital antiferromagnetism (AF) in the vicinity of a single vortex in a cuprate superconductor. We find that when the potential for the orbital AF…
Compelling evidence exists for electronic phase separation in cuprate high-$T_c$ superconductors, emerging near 1/8 hole doping. At these dopings and low temperatures, intertwined charge and spin stripes coexist with more uniformly doped…
We show that, under rather general assumptions, the phase diagram of a quasi-one-dimensional repulsive Fermi system consists of two ordered phases: the density wave, spin or charge, and the superconductivity. It is demonstrated that the…
We report experimental results of ^{75}As and ^{139}La nuclear magnetic resonance (NMR) in the iron-based layered La(O_{1-x}F_{x})FeAs (x= 0.0, 0.04 and 0.11) system. In the undoped LaOFeAs, 1/T_1 of ^{139}La exhibits a distinct peak at T_N…
The recently discovered high-temperature superconductivity in doped quaternary iron oxypnictides correlates experimentally with a magnetic instability. We have used first-principles calculations to determine a magnetic phase diagram of…
We report a systematic investigation of Ba[Fe(1-x)Co(x)]2As2 based on transport and 75-As NMR measurements, and establish the electronic phase diagram. We demonstrate that doping progressively suppresses the uniform spin susceptibility and…
We compute the electronic structure, momentum resolved spectral function and optical conductivity of the new superconductor LaO$_{1-x}$F$_x$FeAs within the combination of the Density functional theory and the Dynamical Mean Field Theory. We…
We performed nuclear magnetic resonance (NMR) measurements to investigate the evolution of spin-density-wave (SDW) and superconducting (SC) states upon electron doping in CaFe_{1-x}Co_{x}AsF, which exhibits an intermediate phase diagram…
Theoretical calculations under the scheme of WIEN2k computer package had been performed on the pristine compound LaOFeAs, as well as on LaO1-xFxFeAs. One factor crucial to the manifestation of superconductivity seems to be fluorine doping;…
The recently discovered FeAs-based materials exhibit a $(\pi,0)$ Spin Density Wave (SDW) in the undoped state, which gives way to superconductivity upon doping. Here we show that due to an interesting topological feature of the band…
Competing orders in condensed matter give rise to the emergence of fascinating, new phenomena. Here, we investigate the competition between superconductivity and charge density wave in the context of layered-metallic compounds, transition…