Related papers: Current-Induced Pair Breaking in Magnesium Diborid…
Measurements of the superconducting upper critical field, H_{c2}, and critical current density, J_c, have been carried out for MgB_2 doped with Ti and/or C in order to explore the problems encountered if these dopants are used to enhance…
Recently it was discovered that, under elevated pressures, MoB$_2$ exhibits superconductivity at a critical temperature, $T_c$, as high as 32 K. The superconductivity appears to develop following a pressure-induced structural transition…
The current distribution across the thickness of a current-carrying rectangular film in the Meissner state was established long ago by the London brothers. The distribution across the width is more complicated but was later shown to be…
A microscopic analysis of the superconducting quantum critical point realized via a pair-breaking quantum phase transition is presented. Finite temperature crossovers are derived for the electrical conductivity, which is a key probe of…
The influence of two important features of magnesium diboride on the macroscopic transport properties of polycrystalline MgB2 is discussed in the framework of a percolation model. While two band superconductivity does not have significant…
We have investigated the behaviour of the depairing current J_{dp} in ferromagnet/superconductor/ferromagnet (F/S/F) trilayers as function of the thickness d_s of the superconducting layers. Theoretically, J_{dp} depends on the…
In the standard theory of superconductivity, the origin of superconductivity is the electron-pairing. The induced current by a magnetic field is calculated by the linear response to the vector potential, and the supercurrent is identified…
Experimental discovery of near-room-temperature superconductivity in highly compressed hydrogen sulfate started a new era in superconductivity. To date, researchers have made the discovery of dozens of superconducting hydride phases with…
We develop a microscopic analysis of superconducting and dissipative currents in junctions between superconductors with d-wave symmetry of the order parameter. We study the proximity effect in such superconductors and show that for certain…
Current transport in polycrystalline magnesium diboride is highly non-uniform (percolative) due to the presence of secondary phases and also due to the intrinsic anisotropy of the material. The influence of secondary phases on the transport…
Magnetic measurements carried out on MgB_2 superconducting round wires have shown that the critical current density J_c(B_a) in wires sheathed by iron can be significantly higher than that in the same bare (unsheathed) wires over a wide…
Fine grained polycrystalline samples of MgB(2) superconductor were synthesized from the elements to contain < 5 % of impurity phases, according to X-ray powder diffractometry. The superconductive transition was sharp with a midpoint Tc =…
In this work we investigate the effect of each different heat treatment stage in the fabrication of Bi2Sr2CaCu2O8+d superconducting wires on intra-grain and inter-grain superconducting properties. We measure magnetic critical temperature Tc…
We present electrical transport, magnetization, and specific heat measurements on bulk MgB2 samples (T_{c} = 38.5 K) synthesized under 200 MPa pressure using a process based on hot isostatic pressing with cooling under pressure. The samples…
A model system consisting of a mesoscopic superconducting grain coupled by Josephson junctions to two macroscopic superconducting electrodes is studied. We focus on the effects of ohmic dissipation caused by resistive shunts and…
Starting from the Ginzburg-Landau energy functional, we discuss how the presence of two order parameters and the coupling between them influence a superconducting ring in the fluctuative regime. Our method is exact, but requires numerical…
The interplay of quantum fluctuations and dissipation in chains of mesoscopic superconducting grains is analyzed, and the results are also applied to nanowires. It is shown that in 1-d arrays of resistively shunted Josephson junctions, the…
Processing methods are described for the development of magnesium diboride wire using the chemical vapor deposition (CVD) to produce long lengths of suitably doped starting boron fiber. It is found that titanium can be co-deposited with the…
Seven years after the discovery of superconductivity in magnesium diboride, the fundamental superconducting properties of this compound are well known and the peculiar current transport in polycrystalline materials is essentially…
We analyze here the behavior near the 2D insulator-superconductor quantum critical point in the presence of a perpendicular magnetic field. We show that with increasing field $H$, the quantum disordered and quantum critical regimes, in…