Spin transfer torque programming dipole coupled nanomagnet arrays

We experimentally demonstrated spin transfer torque (STT) programming of dipole coupled nanomagnets using magnetic tunnel junctions. The STT write operations were performed in conjunction with a clock field used in magnetic quantum cellular automata (MQCA) operations. The spacing and number of nanomagnets in the transmission line strongly affected the STT programming of the individual pillars. These MQCA transmission lines ranged in length from 2 elements to 20 elements, while device sizes ranged between 50 nm × 80 nm and 70 nm × 100 nm with spacing between 10 nm and 15 nm. With the application of the clock field, currents of 100-200 μA are sufficient to STT program the device. The demonstration of STT programming of individual nanomagnets in a dipole coupled array marks a significant step forward for applications such as MQCA logic device.