A magnetoresistive element comprises a nonmagnetic sidewall-current-channel (SCC) structure provided on a surface of the SOT material layer that exhibits the Spin Hall Effect, which is opposite to a surface of the SOT material layer where the magnetic recording layer is provided, and comprising an insulating medium in a central region of the SCC structure, and a conductive medium being a sidewall of the SCC structure and surrounding the insulating medium, making an electric current crowding inside the SOT material layer and the magnetic recording layer to achieve a spin-orbit torque and a higher spin-polarization degree for an applied electric current.