Related papers: Fluctuations Indicate Strong Interlayer Coupling i…
Superconducting transition temperatures Tc of the YBCO film surface and of the YBCO film/substrate interface were measured inductively. It was observed that the interface- Tc is always higher then the surface - Tc. However deposition of…
The resistive properties of layered HTSC BiSrCaCuO in the mixed state are compared with those of thin films of conventional superconductors with weak disorders (amorphous Nb_{1-x}0_{x} films) and with strong disorders (Nb_{1-x}O_{x} films…
Fluctuating superconductivity - vestigial Cooper pairing in the resistive state of a material - is usually associated with low dimensionality, strong disorder or low carrier density. Here, we report single particle spectroscopic,…
The investigation of the penetration depth \lambda_{ab}(T,p) in YBa_2Cu_3O_{7-x} crystals allowed to observe the following features of the superfluid density n_s(T,p)\propto \lambda_{ab}^{-2}(T,p) as a function of temperature T<Tc/2 and…
We present a comprehensive investigation of the Berezinskii-Kosterlitz-Thouless (BKT) transition in ultrathin strongly disordered NbN films. Measurements of resistance, current-voltage characteristics and kinetic inductance on the very same…
Collective modes of bilayered superconducting superlattices (e.g., YBCO) are investigated within the conserving gauge-invariant ladder diagram approximation including both the nearest interlayer single electron tunneling and the…
In type-II superconductors, in the regime of very high applied current density, an abrupt transition is experimentally observed from the mixed state to a highly dissipative regime, probably the normal state. This provokes a high voltage…
We report on a photo-induced transient state of YBa2Cu2O6+x in which transport perpendicular to the Cu-O planes becomes highly coherent. This effect is achieved by excitation with mid-infrared optical pulses, tuned to the resonant frequency…
It is shown that the large effect of heavy ion-irradiation on the thermodynamical properties of the anisotropic superconductor YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ extends well into the superconducting fluctuation regime. The presence of the…
The nature of the underdoped pseudogap regime of the high-temperature superconductors has been a matter of long-term debate. On quite general grounds, one expects that due to their low superfluid densities and short correlation lengths,…
Transport measurements carried out on twinned ybco films are compared to the predictions of a previously proposed model suggesting that the vortices move along the films twin boundaries that behave as rows of Josephson weak links…
By means of the linear dynamic conductivity, inductively measured on epitaxial films between 30mHz and 30 MHz, the transition line $T_g (B)$ to generic superconductivity is studied in fields between B=0 and 19T. It follows closely the…
Strongly disordered superconducting films have been observed to undergo finite temperature transitions to a superinsulating state, of apparently infinite resistance, mirroring superconductivity. Approaching the transition, some of the films…
We propose a weakly coupled two-band model with $d_{x^2-y^2}$ pairing symmetry to account for the anomalous temperature dependence of superfluid density $\rho_s$ in electron-doped cuprate superconductors. This model gives a unified…
In two dimensions, a phase-coherent superconducting state is established via a Berezinskii-Kosterlitz-Thouless (BKT) transition, whose critical temperature $T_{\rm BKT}$ is determined by the global superfluid stiffness in uniform…
The influence of YBa2Cu3O4 (YBCO) superconductor layer (S-layer) with varying thickness d-YBCO = 20 to 50 nm on the magnetic coupling between two La0.67Ca0.33MnO3 (LCMO) ferromagnet layers (F-layer, thickness d-LCMO = 50 nm) in F/S/F…
High superconducting transition temperature is favorable for the applications of superconductors. Some cuprate superconductors have the transition temperatures above 100 K, such as the Hg- or Tl-based 1223 and 1234 phases, but many of them…
We show that strong electric fields of ~ 30 kV cm^(-1) at terahertz frequencies can significantly weaken the superconducting characteristics of cuprate superconductors. High-power terahertz time-domain spectroscopy (THz-TDS) was used to…
YBa2Cu3Ox, the first superconductor discovered with Tc higher than 77 K, is among the most complex cuprates having both CuO chains and plains in the structure. YBa2Cu3O7 (YBCO) exhibits slightly overdoped behavior and further doping is…
It is shown that the temperature of the resistive transition $T_r$ of a superconducting film can be increased by a thin superconducting or normal overlayer. For instance, deposition of a highly conductive thin overlayer onto a dirty…