Takayuki Harada

Trap-controlled space-charge-limited current mechanism in resistance switching at Al∕Pr0.7Ca0.3MnO3 interface

Well-defined metal-insulator-metal trilayered structures composed of epitaxial Pr0.7Ca0.3MnO3 insulator layers, epitaxial LaNiO3 bottom electrodes, and Al metal top electrodes were fabricated on LaAlO3 (100) substrates. The I-V characteristics of the trilayer structures show electric-field-induced resistance switching. The resistance switching ratio of the heterostructures was up to 100 when positive and negative pulsed voltages were applied. Detailed I-V analysis indicates the importance of both trap-controlled space-charge-limited current and Poole–Frenkel effect in resistance switching at Al∕Pr0.7Ca0.3MnO3 interfaces.

Spin-Filter Tunnel Junction with Matched Fermi Surfaces

Efficient injection of spin-polarized current into a semiconductor is a basic prerequisite for building semiconductor-based spintronic devices. Here, we use inelastic electron tunneling spectroscopy to show that the efficiency of spin-filter-type spin injectors is limited by spin scattering of the tunneling electrons. By matching the Fermi-surface shapes of the current injection source and target electrode material, spin injection efficiency can be significantly increased in epitaxial ferromagnetic insulator tunnel junctions. Our results demonstrate that not only structural but also Fermi-surface matching is important to suppress scattering processes in spintronic devices.

Hydrostatic pressure response of an oxide-based two-dimensional electron system

Two-dimensional electron systems with fascinating properties exist in multilayers of standard semiconductors, on helium surfaces, and in oxides. Compared to the two-dimensional (2D) electron gases of semiconductors, the 2D electron systems in oxides are typically more strongly correlated and more sensitive to the microscopic structure of the hosting lattice. This sensitivity suggests that the oxide 2D systems are highly tunable by hydrostatic pressure. Here we explore the effects of hydrostatic pressure on the well-characterized 2D electron system formed at

A versatile patterning process based on easily soluble sacrificial bilayers

{\mathrm{LaAlO}}_{3}\ensuremath{-}{\mathrm{SrTiO}}_{3}

Highly conductive PdCoO2 ultrathin films for transparent electrodes

interfaces [A. Ohtomo and H. Y. Hwang, Nature (London) 427, 423 (2004)] and measure a pronounced, unexpected response. Pressure of

Spectroscopic studies on the electronic and magnetic states of Co-doped perovskite manganite Pr0.8Ca0.2Mn1-yCo yO3 thin films

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Nonmagnetic Sc Substitution in a Perovskite Ferromagnetic Insulator Pr0:8Ca0:2MnO3

GPa reversibly doubles the 2D carrier density

Microfabrication of SrRuO3 thin films on various oxide substrates using LaAlO3/BaOx sacrificial bilayers

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Superconducting coupling across a spin-filtering manganite tunnel barrier with magnetic disorder

at 4 K. Along with the increase of

Spectroscopic Visualization of Vortex Flows Using Dye‐Containing Nanofibers

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