Critical current in a spin injection device

Abstract

We report on direct evidence of the suppression of critical current due to pair-breaking in a superconducting microbridge when the measurement is carried out by injecting spin-polarized carriers instead of normal electrons. A thin layer of La0.7Ca0.3MnO3 was used as the source of spin-polarized carriers. The microbridge was formed on the DyBa2Cu3O7−δ thin film by photolithographic techniques. The design of our spin-injection device allowed us to inject spin-polarized carriers from the La0.7Ca0.3MnO3 layer directly to the DyBa2Cu3O7−δ microbridge (without any insulating buffer layer) making it possible to measure the critical current when polarized electrons alone are injected into the superconductor. Our results confirm the role of polarized carriers in breaking the Cooper pairs in the superconductor.

Electronic and magnetic properties in Fe-based Fe1−xNix, Fe1−xCox, and Fe1−xVx films on W(110)

“…Both Fe and Ni can be grown epitaxially on W(1 1 0): iron as bcc Fe(1 1 0) and nickel as fcc Ni(1 1 1) [8,9]. In the case of the Fe 1Àx Co x alloy film, the high spin polarization at the Fermi level of this alloy makes it an interesting candidate material for use in spin injection devices [10]. Moreover, the structure of this alloy varies as a function of composition, with Fe taking on a bcc and Co an hexagonal close packing (hcp) structure [11,12].…”

Strontium titanate resistance modulation by ferroelectric field effect

“…Furthermore, thanks to the isostructural nature of these compounds, the possibility of matching materials with different physical properties in the same crystalline structure opens new perspectives for oxide electronics. Several examples of perovskite oxide devices have already been realized such as ferroelectric memories, field effect transistors, and ferroelectric field effect or spin injection devices [1][2][3][4][5][6][7].…”