Logical devices based on the antiferromagnetic-antimeron in a ferromagnet nanodot with gain

The antiferromagnetic spintronics is attracting intensive attention due to the recent progress of antiferromagnetism. Especially, the topological magnetic structures, discovered in the antiferromagnetic materials, have opened an alternative path for energy efficient information processing, e.g., constructing logical devices. Herein, we theoretically extend the building block of spintronics devices by utilizing the antiferromagnetic-antimeron, which can be formed in ferromagnet nanodots with gain. A rotational mode of the antiferromagnetic-antimeron is observed under the injection of spin polarized current that originates from the excitation of spin waves propagating along the radial normal of the nanodots. The frequency of rotation (f) can be analytically calculated, expressed in the form of f ∝ k J α, where k is a proportionality coefficient, and J and α are the current density and Gilbert damping, respectively. The value of f is proportional to the current density (J), but inversely proportional to α. Finally, the logical gates based on the antiferromagnetic-antimeron are proposed for Boolean logic operation of OR, XOR, XNOR, and AND. Utilizing the unique dynamic behaviors of the antiferromagnet-antimeron under the injection of current sheds light on the development of the building block of spintronics devices.