A four-state magnetic tunnel junction for novel spintronics applications

Researchers have introduced a new type of MTJ with four resistance states, and successfully demonstrated switching between the states with spin currents. The increased number of states is achieved by replacing one of the magnetic layers with a structure in the form of two crossing ellipses. Such MTJs may enable novel spintronics devices, e.g., multi-level MRAM which stores data much more densely, or neuromorphic memory that meets artificial intelligence challenges in performing cognitive tasks.