%0 Journal Article %K magnetoresistance %K yttrium compounds %K lanthanum compounds %K Polarization %K High temperature superconductors %K Heterojunctions %K Neodymium compounds %K Spin dynamics %K Critical current density (superconductivity) %K Electron transport properties %K Superconducting devices %K Electric conductivity measurement %K Gain measurement %K Magnetic relaxation %K Equilibrium density of pairs %K Joule heating %K Spin polarized quasiparticle injection device %K Transport measurement %A Z.W Dong %A Ramamoorthy Ramesh %A T Venkatesan %A M Johnson %A Z.Y Chen %A S.P Pai %A V Talyansky %A R.P Sharma %A R Shreekala %A C.J Lobb %A R.L Greene %B Applied Physics Letters %D 1997 %G eng %I American Institute of Physics Inc. %P 1718-1720 %R 10.1063/1.120014 %T Spin-polarized quasiparticle injection devices using Au/YBa2Cu3O7/LaAIO3/Nd 0.7Sr0.3MnO3 heterostructures %V 71 %X Oxide heterostructures were used for studies of quasiparticle injection effects in high-Tc superconducting thin films. The effect of injection of spin polarized quasiparticles from a ferromagnetic gate layer was compared to that of unpolarized quasiparticles from a nonmagnetic metallic gate. Transport measurements of the superconducting layer showed strong suppression in the supercurrent by the injection of spin-polarized quasiparticles, and a current gain of as large as five was attained. This is 10 to 30 times larger than the gain of unpolarized injection devices. Such large effects could be useful in a variety of active high-Tc superconductor/colossal magnetoresistance heterostructure based devices. © 1997 American Institute of Physics.