We have studied the local transport properties in an epitaxial YBa2Cu3O7 x (YBCO) film on LaAlO3 (LAO) using variable temperature scanning laser microscope (VTSLM) near the superconducting transition. A map of the superconducting transition temperature ðT c Þ is generated from a series of VTSLM images. The map of T c indicates there are inhomogeneities in the film large enough to create nonunif...

A persistent current switch (PCS) is used for superconducting applications, such as superconducting magnetic energy storage (SMES) system. The authors have proposed a mechanical switch of Y-BaCu-O (YBCO) bulk as a mechanical PCS. In previous study, the authors have successfully reduced a residual resistance by depositing with metal on contact surface. This paper focused on a current carrying ar...

Transport across an La0.7Sr0.3MnO3/YBa2Cu3O7−x (LSMO/YBCO) interface is studied as a function of temperature and surface morphology. For comparison, control measurements are performed in non-magnetic heterostructures of LaNiO3/YBCO and Ag/YBCO. In all cases, YBCO is used as bottom layer to eliminate the channel resistance and to minimize thermal effects. The observed differential conductance re...

In the persistent photoconductivity (PPC) phenomena, illumination of a material with light leads to a long-lived photoconductive state. During illumination of oxygen deficient YBCO near the insulator–metal transition, the illuminated material may even become superconducting. Accompanying the large relative changes in resistance are transport and structural changes as well as changes in the phot...

We investigate the influence of extended scatterers on the finite temperature and finite frequency microwave conductivity of d-wave superconductors. For this purpose we generalize a previous treatment by Durst and Lee, which is based on a nodal approximation of the quasiparticle excitations and scattering processes, and apply it to the analysis of experimental spectra of YBCO-123 and BSCCO-2212...

We report on the spurious suppression effect in lowmicrowave power transmitters by high temperature superconducting (HTS) bandpass filters (BPFs) which are promising for devices requiring BPFs with high-frequency selectivity. Some of the major issues on the power BPFs with HTS planar circuits for wireless communication applications are reviewed. As a case study for the HTS filter and its spurio...

We develop a simple theory of the electromagnetic response of a d-wave supercon-ductor in the presence of potential scatterers of arbitrary s-wave scattering strength and inelastic scattering by antiferromagnetic spin fluctuations. In the clean London limit, the conductivity of such a system may be expressed in " Drude " form, in terms of a frequency-averaged relaxation time. We compare predict...

This paper reports the results of an experimental investigation of the performance of two types of magnetic screens assembled from YBa2Cu3O7− YBCO coated conductors. Since effective screening of the axial dc magnetic field requires the unimpeded flow of an azimuthal persistent current, we demonstrate a configuration of a screening shell made out of standard YBCO coated conductor capable to acco...

We report our studies on single-picosecond electrical pulse switching of YBa2Cu3O7−x (YBCO) grain-boundary bicrystal Josephson junctions. The test structures consisted of coplanar strip (CPS) transmission lines that were patterned in 50 nm thick YBCO films prepared on (100) MgO bicrystal substrates. Each CPS contained a 5 μm wide, 10 μm long microbridge and a 5 μm wide grain-boundary Josephson ...

We consider a bilayer version of the extended t-J model, with a view to computing the form of certain experimentally observable properties. Using the slave-boson decomposition , we show at the mean-field level that in the bilayer system the existence of in-plane d-wave singlet pairing excludes any interplane singlet order for reasonable values of the interplane superexchange parameter. Restrict...