Magnetoelectric domain wall dynamics and its implications for magnetoelectric memory

摘要

Domain wall dynamics in a magnetoelectric antiferromagnet is analyzed, and its implications for magnetoelectric memory applications are discussed. Cr_2O_3 is used in the estimates of the materials parameters. It is found that the domain wall mobility has a maximum as a function of the electric field due to the gyrotropic coupling induced by it. In Cr_2O_3, the maximal mobility of 0.1 m/(s Oe) is reached at E ≈ 0.06 Vm. Fields of this order may be too weak to overcome the intrinsic depinning field, which is estimated for B-doped Cr_2O_3. These major drawbacks for device implementation can be overcome by applying a small in-plane shear strain, which blocks the domain wall precession. Domain wall mobility of about 0.7 m/(s Oe) can then be achieved at E = 0.2 Vm. A split-gate scheme is proposed for the domain-wall controlled bit element; its extension to multiple-gate linear arrays can offer advantages in memory density, programmability, and logic functionality.