Magnetic skyrmion diode based on symmetry breaking of potential energy barriers

Magnetic skyrmion are topologically nontrivial spin structures that can be stabilized on a ferromagnetic background with the Dzyaloshinskii-Moriya interaction. They represent the ultimate small achievable size for nonvolatile magnetic memory elements and can be driven by low-density spin-polarized currents. Thus, they are being proposed as information carriers for a new generation of ultra-dense magnetic memories and logic devices. For skymion-based potential applications, we present a skyrmion diode operated by a unidirectional skyrmion transport, which has recently been realized by us. We manipulate the skyrmion transport by engineering asymmetric shapes of geometric structures. Furthermore, we develop a simple method to describe the underlying mechanism behind the unidirectional skyrmion transport by characterizing the topography of potential energy surfaces from a purely geometric perspective. Our approach enables a deeper physical insight into skyrmion transport manipulation and efficient design of skyrmion-based devices in geometric structures.