Collective magnetization flux closure state with circular array of single-domained nanomagnets: Magnetization reversal and chirality control.

A practical approach is theoretically proposed for the formation and manipulation of the chirality of a magnetization flux closure (MFC) state. It is realizable over a circular array consisting of a few single-domained (SD) nanomagnets. The entire array size is smaller than 100 nm. The investigation is performed by numerical calculations based on the Landau–Lifshitz–Gilbert equation. Parameters concerning the formation and stability of the MFC state are obtained for the circular arrays of five and six nanomagnets. The effect of the applied field orientation on the manipulation of the chirality is investigated. In addition, the critical distance LC is determined, beyond which the effect of magnetic coupling between adjacent arrays becomes negligible. The corresponding maximum density of arrays without the magnetic coupling effect is thus estimated. Our work makes the application of the collective MFC state in the ultrahigh density magnetic storage possible, exceeding 200 Gbits/in2. [ABSTRACT FROM AUTHOR]