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Recent discovery of the topological crystalline insulator SnTe has triggered a search for topological superconductors, which have potential application to topological quantum computing. The present work reports on the superconducting properties of indium doped SnTe thin films. The (100) and (111) oriented thin films were epitaxially grown by pulsed-laser deposition on (100) and (111) BaF2 crystalline substrates, respectively. The onset superconducting transition temperatures are about 3.8K for (100) and 3.6K for (111) orientations, slightly lower than that of the bulk. Magneto-resistive measurements indicate that these thin films may have upper critical fields higher than that of the bulk. With large surface-to-bulk ratio, superconducting indium doped SnTe thin films provide a rich platform for the study of topological superconductivity and potential device applications based on topological superconductors. [ABSTRACT FROM AUTHOR]

We show the observation of the coexistence of bulk superconductivity and magnetic ordering in CeO1-xFxBiS2 (x = 0-1.0) prepared by annealing under high pressure. In the CeO1-xFxBiS2 system, both superconductivity and two types of ferromagnetic-like ordering with magnetic transition temperatures of 4.5 and 7.5 K are induced upon systematic F substitution. This fact suggests that carriers generated by the substitution of O by F are supplied to not only the BiS2 superconducting layers but also the CeO blocking layers. Furthermore, the highest superconducting transition temperature is observed when the ferromagnetic-like transition temperature increases, which implies that superconductivity and this magnetic ordering are linked to each other in the CeO1-xFxBiS2 system. [ABSTRACT FROM AUTHOR]

The effects of uniaxial strain and hydrostatic pressure on YBa2Cu4O8 were investigated through magnetic measurements under stresses of up to 25 GPa. The out-of-plane (along the c-axis), in-plane (along the c-plane), and hydrostatic contractions all initially bring about an increase in the superconducting transition temperature (Tc). In the case of the out-of-plane and in-plane contractions, the Meissner signal disappears at a stress corresponding to about 10 GPa. However, under the hydrostatic contraction, the maximum Tc was about 100K at 9-12 GPa, and the Meissner effect was observed at pressures of at least 16 GPa. [ABSTRACT FROM AUTHOR]

Upon a certain DNA damage including cisplatin treatment, p73 is stabilized and exerts its growth-suppressive and/or proapoptotic function. However, the precise molecular basis by which the intracellular levels of p73 are regulated remains unclear. In the present study, we have identified RanBPM as a novel binding partner of p73aby yeast-based two-hybrid screening, and also found that RanBPM has an ability to stabilize p73a. GST pull-down assays and co-immunoprecipitation experiments revealed that RanBPM directly bound to the extreme COOH-terminal region of p73a, whereas it failed to interact with p53. Co-expression of RanBPM with p73aresulted in the nuclear translocation of RanBPM, and both proteins co-localized in cell nucleus as examined by indirect immunofluorescent staining. It is worth noting that the expression of RanBPM inhibited the ubiquitination of p73a, and thereby prolonged its half-life. Subsequent studies demonstrated that the proapoptotic activity of p73awas significantly enhanced in the presence of RanBPM. Taken together, our present findings implicate a novel role for RanBPM in the regulation of p73 stability and function.Oncogene (2005) 24, 938-944. doi:10.1038/sj.onc.1208257 Published online 22 November 2004 [ABSTRACT FROM AUTHOR]

We show that Xe ion irradiation with 80 MeV to GdBa2Cu3Oy-coated conductors creates different morphologies of columnar defects (CDs) depending on the irradiation angles θi relative to the c-axis: continuous CDs with a larger diameter are formed for oblique irradiation at θi = 45°, whereas the same ion beam at a different angle (θi = 0°) induces the formation of discontinuous CDs. The direction-dependent morphologies of CDs significantly affect the angular behavior of the critical current density Jc. In particular, low-energy irradiation defects induce further improvement of Jc in a unique combination of irradiation angles of θi = 0° and ±45°: discontinuous CDs at θi = 0° and crossed CDs at θi = ±45° provide correlated pinning in a wide angular range, which is more strongly enhanced by each other via the pinning of kinks. [ABSTRACT FROM AUTHOR]

The loss-less electrical current-carrying capability of type II superconductors, measured by the critical current density Jc, can be increased by engineering desirable defects in superconductors to pin the magnetic vortices. Here, we demonstrate that such desirable defects can be created in superconducting FeSe0.5Te0.5 films by 6 MeV Au-ions irradiations that produce cluster-like defects with sizes of 10–15 nm over the entire film. The pristine FeSe0.5Te0.5 film exhibits a low anisotropy in the angular dependence of Jc. A clear improvement in the Jc is observed upon Au-ion irradiation for all field orientations at 4.2 K. Furthermore, a nearly 70% increase in Jc is observed at a magnetic field of 9 T applied parallel to the crystallographic c-axis at 10 K with little reduction of the superconducting transition temperature Tc. Our studies show that a dose of 1 × 1012 Au cm–2 irradiation at a few MeV is sufficient in order to provide a strong isotropic pinning defect landscape in iron-based superconducting films. [ABSTRACT FROM AUTHOR]

We performed magneto-optical (MO) measurements on FeTe0.5Se0.5 thin films grown on LaAlO3 (LAO) and Yttria-stabilized zirconia (YSZ) single-crystalline substrates. These thin films show superconducting transition temperature Tc ∼19 K, 4 K higher than the bulk sample. Typical roof-top patterns can be observed in the MO images of thin films grown on LAO and YSZ, from which a large and homogeneous critical current density Jc over at 5 K was obtained. Magnetic flux penetration measurement reveals that the current is almost isotropically distributed in the two thin films. Compared with bulk crystals, FeTe0.5Se0.5 thin film demonstrates not only higher Tc, but also much larger Jc, which is attractive for applications. [ABSTRACT FROM AUTHOR]

We report the successful fabrication of mono- and seven-core superconducting wires of FeSe1 [?] xTex using an in situ Fe-diffusion process based on the powder-in-tube (Fe-diffusion PIT) method. The reacted layers in these wires were found to have composite structure with the composition nearly FeSe and FeTe for the inner and outer layers, although a single layer of composition FeSe0.5Te0.5 was supposed to be formed. The self-field transport Jc values at 4.2 K were found to be 226.2 A cm [?] 2 and 100.3 A cm [?] 2 respectively for mono- and seven-core wires. The Jcs of these wires dropped rapidly at low fields and then showed a gradual decrease with increasing magnetic fields. In addition, the seven-core wire showed higher Jc than the mono-core wire under higher magnetic fields, indicating that the seven-core wire of FeSe1 [?] xTex superconductor produced using the Fe-diffusion PIT method is advantageous for superconducting wire applications under high magnetic fields. [ABSTRACT FROM AUTHOR]

We report the results of magnetization measurements with the magnetic field applied along the c axis on superconducting La1.9 Ca1.1 Cu2 O6+δ single crystals processed under ultrahigh oxygen pressure. Strong fluctuation effects were found in both low- and high-field regimes. Scaling analysis of the high-field magnetization data near the critical temperature (Tc = 53.5 K) region reveals the characteristics of critical fluctuation behavior of quasi-two-dimensional (2D) superconductivity, described by Ginzburg-Landau theory using the lowest Landau level approximation. Low-field magnetic susceptibility data can be successfully explained by the Lawrence-Doniach model for a quasi-2D superconductor, from which we obtained the ab plane Ginzburg-Landau coherence length of this system, ξab(0) = 11.8 ± 0.9 Å. The coherence length along the c axis, ξc(0), is estimated to be about 1.65 Å, which is in between those of 2D cuprate systems, such as Bi2 Sr2 Ca2 Cu3 O10 and Bi2 Sr2 CaCu2 O8, and quasi-three-dimensional (3D) cuprate systems, such as overdoped La2-x Srx Cu O4 and YB a2 Cu3 O7-δ. Our studies suggest a strong interplay among the fluctuation effects, dimensionalities, and the ratios of the interlayer Cu-O plane spacing, s, to the c-axis coherence lengths. A high s/ξc(0) was observed in the high-pressure oxygenated La1.9 Ca1.1 Cu2 O6+δ, and that apparently drives this system to behave more like a quasi-2D superconductor. [ABSTRACT FROM AUTHOR]

The effects of uniaxial strain and hydrostatic pressure on Hg0.83Re0.18Ba2Ca2.4Cu3.6O14[Hg0.83(Re0.18)-1223] were investigated by ac magnetic measurements under stress corresponding to a pressure of 20 GPa at maximum. According to a previous thermal study based on the Ehrenfest relation, in-plane contraction should increase the superconducting transition temperature Tc, whereas out-of-plane contraction should decrease Tc. This suggests that the increase in Tc under hydrostatic-pressure contraction must be smaller than that under in-plane contraction. However, the present uniaxial-strain experiments revealed enhancement of Tc under both in-plane and out-of-plane contraction, and the largest enhancement was observed under hydrostatic-pressure contraction. According to a band calculation, all contraction styles induce hole doping from the HgO blocks to the CuO2 blocks, and hydrostatic-pressure contraction yields the largest hole doping among three contractions. This behavior explains well a series of changes in Tc in the stress region of below 8 GPa. More specifically, under hydrostatic-pressure contraction, Tc exhibited an increase, a decrease, and another increase with increasing pressure, and this multistep change is similar to that observed in Bi-2223-type cuprate superconductors, suggesting that it is necessary to distinguish the effect of strain on the middle CuO2 plane in the three-CuO2-plane package from that on the outer planes. [ABSTRACT FROM AUTHOR]