Magnetic Sensor Devices Based on Ordered Planar Arrangements of MnAs Nanocluster

We propose planar magneto-electronic devices based on accurately positioned and shaped ferromagnetic MnAs nanoclusters in NiAs structure. The prototype discussed consists of a small hexagon-shaped cluster sandwiched between two elongated clusters with fixed magnetic orientations. The magnetization of the center cluster is free and can be rotated by an external magnetic field. Our
ab initio
calculations yield a strong dependence of the conductance as a function of the direction of the external magnetic field which exhibits an in-plane symmetry of 360 degrees.