Related papers: Using controlled disorder to distinguish $s_\pm$ a…
Impurity doping like Zn atoms in cuprates were systematically studied to provide important information on the pseudogap phase because this process substantially reduces $T_c$ without effect $T^*$. Despite many important results and…
The sign-reversing fully gapped superconducting state, which is expected to be realized in oxypnictide superconductors, can be prominently affected by nonmagnetic impurities due to the interband scattering of Cooper pairs. We study this…
We have carried out an investigation of the structural, magnetic, transport and superconducting properties of Fe$_{1+z}$Te$_{1-x-y}$Se$_x$S$_y$ ceramic compounds, for $z=0$ and some specific Se (0$\leq$ x $\leq$ 0.5) and S (0 $\leq$ y…
Resistivity r(T), Hall coefficient RH(T), superconducting temperature Tc, and the slope of the upper critical field -dHc2/dT were studied in poly- and single-crystalline samples of the Fe-based superconductor Lu2Fe3Si5 irradiated by fast…
More recently STM experimets present firm evidence of some kind of charge modulation in underdoped cuprates. The peculiar observations of the above experiments are located in the so called pseudo-gap region of the phase diagram, just over…
The understanding of disorder has profoundly influenced the development of condensed matter physics, explaining such fundamental effects as, for example, the transition from ballistic to diffusive propagation, and the presence of quantized…
It has long been established that disorder has profound effects on unconventional superconductors and it has been suggested repeatedly that observation and analysis of these disorder effects can help to identify the order parameter…
The superconductor-insulator transition as a paradigm of quantum phase transitions has attracted tremendous interest over the past three decades. While the magnetic field and carrier density can be tuned to drive the transition, the role of…
The impurity concentration dependence of superconducting transition temperature $T_c$ is studied within the framework of two band model of order parameter anisotropy. Both intraband and interband electron scattering by nonmagnetic and…
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…
London penetration depth, $\lambda(T)$, was measured in single crystals of SrFe$_2$(As$_{1-x}$P$_x$)$_2$ ($x=$0.35) iron - based superconductor. The influence of disorder on the transition temperature, $T_c$, and on $\lambda(T)$ was…
We investigate the band structure, nematic state and superconducting gap structure of two selected FeSe single crystals containing different amount of disorder. Transport and angle-resolved photoemission spectroscopy measurements show that…
We analyze antiferromagnetism and superconductivity in novel $Fe-$based superconductors within the itinerant model of small electron and hole pockets near $(0,0)$ and $(\pi,\pi)$. We argue that the effective interactions in both channels…
We revise the problem of the density of states in disordered superconductors. Randomness of local sample characteristics translates to the quenched spatial inhomogeneity of the spectral gap, smearing the BCS coherence peak. We show that…
We consider the far-infrared and the microwave conductivities of a two-band superconductor with non-magnetic impurities. The strong coupling expressions for the frequency and temperature dependent conductivity of a two-band superconductor…
Competition between superconductivity and disorder plays an essential role in understanding the metal-insulator transition. Based on the Bogoliubov-de Gennes equation, we studied an s-wave superconductor with both spin-orbit coupling and…
An general survey of the superconducting (SC) gap study in the title compounds by point-contact (PC) spectroscopy is presented. The SC gap was determined from dV/dI of PCs employing the well-known theory of conductivity for normal…
We study the superconducting proximity effect between a conventional semiconductor and a disordered s-wave superconductor. We calculate the effective momentum relaxation rate in the semiconductor due to processes involving electron…
We report theoretical and experimental studies of the effect of Zn-impurity in Fe-based superconductors. Zn-impurity is expected to severely suppress sign reversed s$_\pm$ wave pairing. The experimentally observed suppression of T$_c$ under…
We analyze the effect of weak disorder on the competition between antiferromagnetic order and superconductivity in a model for iron-based superconductors. Under the assumption of an approximate particle-hole symmetry we show that…