Enhanced spin accumulation obtained by inserting low-resistance MgO interface in metallic lateral spin valves.

We have systematically investigated the interface contributions to the spin injection characteristics in permalloy/MgO/Ag lateral spin valves. The spin valve signal remarkably increases with MgO thickness and reaches a maximum when the interface resistance is about 100 fΩ m² for 1 nm thick MgO, which is two orders of magnitude lower than that of the typical tunnel junction. Our quantitative analysis based on the spin-dependent diffusion equation considering variable spin polarization in the MgO layer well describes the observed trend in the spin valve signals. [ABSTRACT FROM AUTHOR]