Programmable Racetrack for Magnetic Domain Wall Motion via Local Tuning of Exchange Biased Field

To overcome memory bottleneck issues in memory-centric chip technologies, in-memory computing has been considered an alternative route involving simultaneous data storage and computing in a memory network. In the context of spintronics, a memory-in-logic device based on spin-transfer-torque or spin-orbit-torque magnetoresistive random-access memory, and a magnetic domain wall (DW) racetrack has been studied. To expand the functionalities of a conventional magnetic DW racetrack, the study devises a reprogrammable exchange-biased DW racetrack with local engineering of the exchange bias field (HE) in continuous magnetic films without requiring a lithography process for specific patterning of the films. Furthermore, current-driven and field-driven DW motion along the exchange-biased racetrack is demonstrated. Additionally, within the route of the locally different exchange-biased racetrack, a gate function can be performed to guide or stop DW motion by locally tuning HE. The complex maze racetrack is rewritable, and multiple input channels can be controlled. Local heating allows the exchange bias magnetic field to be set differently depending on the location. This can write racetracks in the uniform film along which the magnetic domain walls can move, and new tracks can be created again by reheating local areas. image