Related papers: Peak effect and its evolution with defect structur…
We have grown superconducting TiN films by atomic layer deposition with thicknesses ranging from 6 to 89 nm. This deposition method allows us to tune the resistivity and critical temperature by controlling the film thickness. The microwave…
The competition between intrinsic disorder in superconducting YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ (YBCO) thin films and an ultradense triangular lattice of cylindrical pinning centers spaced at 30 nm intervals results in an ordered Bose glass…
The temperature dependence of the microwave surface impedance and conductivity are used to study the pairing symmetry and properties of cuprate superconductors. However, the superconducting properties can be hidden by the effects of…
An advanced mask-less nanofabrication technique, focused electron beam-induced deposition (FEBID), has been employed on epitaxial Nb thin films for their ferromagnetic decoration by an array of Co stripes. These substantially modify the…
Vortex thermal fluctuations in heavily underdoped Bi2Sr2CaCu2O8+d (Tc=69.4 K) are studied using Josephson plasma resonance (JPR). From the data in zero magnetic field, we obtain the penetration depth along the c-axis, lambda_{L,c}(0) = 229…
The effect of thermal phase fluctuations (TPF's) on the ab-plane penetration depth, lambda(T), of thin YBa2Cu3O(7-delta) (YBCO) films is found to be much smaller than expected from the paradigm of cuprates as weakly-coupled 2D…
Pr$_{1-x}$Ca$_x$Ba$_2$Cu$_3$O$_{7-\delta}$($x\approx$0.5) thin films have been grown on SrTiO$_3$ and YSZ substrates by the pulsed laser ablation. The substrate temperature dependence of orientation and superconducting poperties were…
Mechanisms of vortex dynamics and pinning and self-field effects which could account for the thickness dependence of the critical current density J_c of superconducting films are addressed. It is shown that at low magnetic fields B, the 2D…
Rectification of microwave radiation (20-40 GHz) by a line boundary between two two-dimensional metals on a silicon surface was observed and investigated at different temperatures, in-plane magnetic fields and microwave powers. The…
We report on the evolution with magnetic field and temperature of the vortex lattice (VL) in fully-oxygenated YBa2Cu3O7 as studied by time-of-flight small angle neutron scattering. Using the HFM/EXED beamline, we have obtained data up to…
When a droplet impacts a liquid film, a vortex ring form and govern momentum and species transport. We experimentally investigate vortex ring formation, propagation and instability during droplet impact onto liquid films, with particular…
We investigate the physics of the microwave response in YBa$_{2}$Cu$_{3}$O$_{7-\delta}$, SmBa$_{2}$Cu$_{3}$O$_{7-\delta}$ and MgB$_{2}$ in the vortex state. We first recall the theoretical basics of vortex-state microwave response in the…
The effect of $\alpha$-particle irradiation on a NdFeAs(O,F) thin film has been investigated to determine how the introduction of defects affects basic superconducting properties, including the critical temperature $T_c$ and the upper…
We investigate the effect of the anisotropy and of the directional pinning in YBa$_2$Cu$_3$O$_{7-x}$ films grown by pulsed laser ablation from targets containing BaZrO$_3$ at 5% mol. BaZrO$_3$ inclusions self-assemble to give nanorods…
The surface resistance (Rs) and the real part (sigma_1) of the microwave complex conductivity of a ~380 nm-thick polycrystalline MgB2 film with the critical temperature (Tc) of 39.3 K were investigated at ~8.5 GHz as a function of…
We have measured the power dependent microwave properties of a weak link in a YBa2Cu3O7 thin film formed by writing a line of damage using a focused ion beam. The measurement was made using a parallel plate resonator at 5.5 GHz with the…
In magnetic superconductors a moving vortex lattice is accompanied by an ac magnetic field which leads to the generation of spin waves. At resonance conditions the dynamics of vortices in magnetic superconductors changes drastically,…
We observe pronounced oscillations in differential reflectivity of 9 nm and 60 nm BaFe\textsubscript{2}As\textsubscript{2} (Ba-122) thin films using ultrafast optical spectroscopy. Our studies show that the oscillations result from…
We report observations of spontaneous formation of magnetic flux lines during a rapid quench of YBa$_{2}$Cu$_{3}$O$_{7-\delta}$ films through T$_{c}$. This effect is predicted according to the Kibble-Zurek mechanism of creation of…
The peak effect in weakly pinned superconductors is accompanied by metastable vortex states. Each metastable vortex configuration is characterized by a different critical current density J_c, which mainly depends on the past thermomagnetic…