Huge magnetoresistance induced by half-metal–semiconductor phase transition in a one-dimensional spin chain: a first-principles study

Abstract

In experimental studies, magnetoresistance (MR) values of 10³ are hard to reach for conventional single-molecule spin-valves. Motivated by a recent experiment [Nano Lett., 2016, 16, 577–582], where tailored Co-salophene-based all-spin molecular devices are successfully realized, we demonstrate the functionality of a Co-salophene-based spin chain without magnetic electrodes. By using nonequilibrium Green's functions in combination with density functional theory, we find that the maximum MR ratio of this spin chain can reach 10⁶ by manipulating its spins in a controlled way, which is several orders of magnitude higher than previously reported experimental values. As the Co-salophene-based spin chain has been successfully synthesized, we are highly expectant of the experimental realization of huge MR ratios.