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An unconventional method of nonlocal spin detection is demonstrated in mesoscopic lateral spin valves at room temperature. Clear nonlocal spin signals are detected between the two ends of an extended ferromagnetic spin detector. This is different from the conventional method in which the nonlocal voltage is measured between the spin detector and the nonmagnetic channel. The results can be understood as spatially non-uniform absorption of a pure spin current into the spin detector across a low-resistance oxide interface. [ABSTRACT FROM AUTHOR]

Cobalt/copper nonlocal spin valve devices with AlOx barriers are fabricated for the purpose of spin-transfer with a pure spin current. The submicron planar device consists of a Co spin injector (F1), a Co spin detector (F2), and a Cu channel. The F2 Co electrode is only 2.5 nm thick, but sizable nonlocal spin signals of 2–4 mΩ are measured at 4.2 K. The spin-transfer switching has been achieved with the assistance of a magnetic field. The magnetizations of F1 and F2 electrodes are set to an antiparallel state by sweeping the magnetic field. The magnetic field is then held at a value smaller but close to the switching field of F2. A small dc current (0.1–1 mA) is sufficient to switch F2 into being parallel with F1. Analysis has been done to rule out possible artifacts due to Oersted fields. [ABSTRACT FROM AUTHOR]

The vortex motion in Cu0.03TaS2 has been investigated by resistivity results with a special electrode arrangements. The vortex behaviors for H c are completely different from that for H ab. The analysis indicates that when H ab, the sharp ρ - T transition is the superconductive-normal transition while for H c, the broadened ρ - T transition is caused by the suppression of the superconducting weak link between the S-Ta-S layers. The existence of the vortex pancake in Cu0.03TaS2 is contradictory to the Clem's model, further demonstrating that the models for high temperature cuprates superconductors are not applicable to the layered transition metal dichalcogenides. [ABSTRACT FROM AUTHOR]

Cobalt-copper nonlocal spin valves are fabricated by shadow evaporation through nanoscale masks. The thickness of Co electrodes is varied and the spin diffusion length of the Cu channel is determined. Short spin diffusion lengths are found in devices with thick (>20 nm) Co layers. Co impurities are introduced into the Cu channel in the shadow evaporation process during the fabrication, and the impurities cause spin-flip scattering. The amount of Co impurities can be reduced by decreasing the thicknesses of Co electrodes. Spin diffusion lengths of ∼400 nm at 295 K and ∼800 nm at 4.2 K are measured in devices with thin (<10 nm) Co layers. [ABSTRACT FROM AUTHOR]