相关论文: Superfluid density of the $\pm$s-wave state for th…
We study the impurity scattering on the $\pm$s-wave superconductor, with realistic parameters for the Fe-pnictide superconductors. Using $\mathcal{T}$-matrix method, generalized for the two bands, we found that impurity scattering of the…
Based on a phenomenological model and the Kubo formula, we investigate the superfluid density $\rho_s(T)$ and then the penetration depth $\lambda(T)$ of the iron-based superconductors in the coexistence region of the spin-density-wave(SDW)…
We consider the superfluid density $\rho_s (T)$ in a two-band superconductor with extended s-wave symmetry ($s^+$) in the presence of non-magnetic impurities and apply the results to Fe-pnictides. We show that the behavior of the superfluid…
The two gaps in a two-band clean s-wave superconductor are evaluated self-consistently within the quasiclassical Eilenberger weak-coupling formalism with two in-band and one inter-band pairing potentials. Superfluid density, free energy and…
We study the dependence of the superconducting gaps on both the disorder and the temperature within the two-band model for iron-based materials. In the clean limit, the system is in the $s_\pm$ state with the sign-changing gaps. Scattering…
We study the impurity suppression of the critical temperature $T_c$ of the FeAs superconductors theoretically based on the the $\pm$s-wave pairing state of a two band model. The effects of non-magnetic and magnetic impurities are studied…
We investigate the effect of magnetic impurities on the local quasiparticle density of states (LDOS) in iron-based superconductors. Employing the two-orbital model where 3$d$ electron and hole conduction bands are hybridizing with the…
Irradiation of superconductors with different particles is one of many ways to investigate effects of disorder. Here we study the disorder-induced transition between $s_\pm$ and $s_{++}$ states in two-band model for Fe-based superconductors…
The quasiparticle states around a nonmagnetic impurity in electron-doped iron-based superconductors with spin-density-wave (SDW) order are investigated as a function of doping and impurity scattering strength. In the undoped sample, where a…
We study the evolution with temperature of quasiparticle bound states around non-magnetic impurities in d-wave superconductors. The associated local density of states has a fourfold symmetry which has recently been observed in Zn-doped…
We report microwave surface impedances of FeSe$_{0.4}$Te$_{0.6}$ single crystals measured at 12, 19, and 44 GHz. The penetration depth exhibits a power law behavior, $\delta \lambda_L=\lambda_L (T)-\lambda_L (0) \propto CT^n$ with an…
One of the features of the unconventional $s_\pm$ state in iron-based superconductors is possibility to transform to the $s_{++}$ state with the increase of the nonmagnetic disorder. Detection of such a transition would prove the existence…
Employing the four-band tight-binding model we study theoretically the doping dependence of the spin response in the normal state of novel Fe-based pnictide superconductors. We show that the commensurate spin density wave (SDW) transition…
The $s_\pm$ and $s_{++}$ models for the superconducting state are subject of intense studies regarding Fe-based superconductors. Depending on the parameters, disorder may leave intact or suppress $T_c$ in these models. Here we study the…
Effects of disorder on electron-doped iron pnictides are investigated systematically based on self-consistent Bogoliubov-de Gennes equations. Multiply impurities with same scattering potential (SP) are randomly distributed in a square…
A two-band model with repulsive interband coupling and interband {\it transport} (potential) scattering is considered to elucidate their effects on material properties. In agreement with previous work, we find that the bands order…
Within the two-orbital model for BiS$_{2}$-based superconductors, the effect from a single nonmagnetic impurity scattering on the superconducting-state is investigated in terms of the T-matrix approach. By considering three kinds of the…
We have measured the reflectivity spectra of the iron based superconductor LiFeAs (Tc = 17.6 K) in the temperature range from 4 to 300 K. In the superconducting state (T < Tc), the clear opening of the optical absorption gap was observed…
The detailed optical properties of the multiband iron-chalcogenide superconductor FeTe$_{0.55}$Se$_{0.45}$ have been reexamined for a large number of temperatures above and below the critical temperature $T_c=14$ K for light polarized in…
The London penetration depth, $\lambda(T)$, was measured in a single crystal V$_{3}$Si. The superfluid density obtained from this measurement shows a distinct signature of two almost decoupled superconducting gaps. This alone is…