An Ultrafast Image Recovery and Recognition System Implemented With Nanomagnets Possessing Biaxial Magnetocrystalline Anisotropy

A circular magnetic disk with biaxial magnetocrystalline anisotropy has four stable magnetization states which can be used to encode a pixel’s shade in a black/gray/white image. By solving the Landau–Lifshitz–Gilbert equation, we show that if moderate noise deflects the magnetization slightly from a stable state, it always returns to the original state, thereby automatically denoising the corrupted image. The same system can compare a noisy input image with a stored image and make a matching decision using magnetic tunnel junctions. These tasks are executed at ultrahigh speeds (
$\sim$
2 ns for a
$512 \times 512$
pixel image).