TOPOLOGICAL INSULATORS AS EFFICIENT ROOM-TEMPERATURE SOURCES OF SPIN-TRANSFER TORQUE FOR NON-VOLATILE

Recent discoveries indicate that the Rashba-Edelstein effect within the topological surface state of 3-dimensional topological insulator films can produce a current-induced torque on an adjacent magnetic device at room temperature that is at least a factor of ten more efficient than any other known mechanism for controlling magnetic devices. This proposal seeks to understand and optimize this effect, and to apply it to develop non-volatile magnetic logic devices operating at levels of current and power reduced by orders of magnitude compared to the capabilities of existing technologies. Specifically, the proposed research will: (1) Determine how to optimize the topological-insulator material and the carrier Fermi level to maximize the efficiency of the spin torque that is generated. (2) Determine the best way to integrate a high-resistivity magnetic material with a high-quality topological-insulator thin film for efficient magnetic manipulation at room temperature. (3) Begin the development of nonvolatile logic devices based on (topological insulator)/(high-resistivity magnet) bilayers.