Nonlocal spin transports in nanopillar-based lateral spin valve

A different type lateral spin valve structure consisting of a pair of the closely located Permalloy nanopillars on a uniform copper film has been developed. From the bias-current and temperature dependences of the spin signal, the nanopillar lateral spin valve was found to have several advantages for generating the pure spin current over the conventional lateral spin valves. We also show that the limitation of the generating spin current can be enhanced by increasing the number of the spin injectors.