Researchers from Tohoku University developed new ultra-small (single-digit nanometer scale) magnetic tunnel junctions (MTJs) that have sufficient retention properties and yet can be switched by a current.

Shape anisotropy and interfacial anisotropy MTJs (Tohoku University)

Tohoku University developed 20-nm CoFeB/MgO-based MTJs in 2010, in which an "interfacial anisotropy" at the CoFeB/MgO interface was utilized. But these will not work at under 20-nm. The researchers now used a "shape anisotropy" to achieve the smaller MTJs.