Related papers: Multiple Superconducting Gaps, Anisotropic Spin Fl…
The coexisting regime of spin density wave (SDW) and superconductivity in the iron pnictides represents a novel ground state. We have performed high resolution angle-resolved photoemission measurements on NaFe1-xCoxAs (x = 0.0175) in this…
The magnetic anisotropy af a rectangular Cu-O-Cu bond is investigated in second order of the spin-orbit interaction. Such a bond is characteristic for cuprates having edge sharing CuO_2 chains, and exists also in the Cu_3O_4 plane or in…
The superconducting gap symmetry is investigated by $^{125}$Te NMR measurements on Sc$_6M$Te$_2$ ($M$ = Fe, Co) without spatial inversion symmetry. The spin susceptibility obtained from the Knight shift $K$ is suppressed below the…
We study theoretically the onset of nonuniform superconductivity in a one-dimensional single wire in presence of Zeeman (or exchange field) and spin-orbit coupling. Using the Green's function formalism, we show that the spin-orbit coupling…
We study Coulomb correlation effects and their role in superconductivity of $\varepsilon$-iron under pressure from 12 to 33 GPa by using a combination of density functional and dynamical mean-field theory. Our results indicate a persistence…
In the copper-oxide parent compounds of the high-transition-temperature superconductors, the valence electrons are localized, one per copper site, due to strong intraatomic Coulomb repulsion. A symptom of the localization is…
The presence of a non-centrosymmetric crystal structure and in-plane mirror symmetry allows an Ising spin-orbit coupling to form in some two-dimensional materials. Examples include transition metal dichalcogenide superconductors like…
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…
The spin dynamics of high temperature superconductors measured by inelastic neutron scattering is reviewed. The spin susceptibility evolves a lot with increasing doping from the undoped insulating state to the overdoped metallic state. In…
Unconventional superconductivity often competes or coexists with other electronic orders. In iron-based superconductors, relationship between superconductivity and the nematic state, where the lattice rotational symmetry is spontaneously…
We study the pairing mechanism in iron pnictide superconductors based on the five-orbital Hubbard-Holstein model. Due to Fe-ion oscillations, the s-wave superconducting (SC) state without sign reversal (s_{++}-wave state) is induced by…
We show by means of the theory of the order parameter phase fluctuations that the temperature of "closing" (or "opening") of the gap (and pseudogap) in the electron spectra of superconductors with anisotropic order parameter takes place…
We derive gap equations for superconductivity in coexistence with ferromagnetism. We treat singlet states and triplet states with either equal spin pairing (ESP) or opposite spin pairing (OSP) states, and study the behaviour of these states…
We present a phenomenological theory of quasiparticle scattering and transport relaxation in the normal state of iron pnictides based on the simplified two-band model coupled via spin fluctuations. In analogy with anomalous properties of…
We consider a general Hamiltonian describing coexistence of itinerant ferromagnetism, spin-orbit coupling and mixed spin-singlet/triplet superconducting pairing in the context of mean-field theory. The Hamiltonian is diagonalized and exact…
Tunneling anisotropic magnetoresistance (TAMR) effect, discovered recently in (Ga,Mn)As ferromagnetic semiconductors, arises from spin-orbit coupling and reflects the dependence of the tunneling density of states in a ferromagnetic layer on…
Superconductivity in quasi-one-dimensional Li$_{0.9}$Mo$_6$O$_{17}$ emerges from an exotic, non-metallic normal state that exhibits signatures of Tomonaga-Luttinger liquid behavior, emergent symmetry and excitonic order. The high upper…
The interplay between spin-orbit interaction (SOI) and magnetism produces interesting phenomena in superconductors. When a two-dimensional (2D) system with strong SOI is coupled to an $s$-wave superconductor, an in-plane magnetic field can…
Altermagnetic (AM) fluctuations are a new class of collinear spin fluctuations whose role in mediating superconductivity faces a fundamental tension: their $\Gamma$-point peak favors intra-orbital spin-triplet pairing, while their spin…
Within the fermion-spin theory, the physical properties of the electron pairing state in the copper oxide materials are discussed. According to the common form of the electron Cooper pair, it is shown that there is a coexistence of the…