Supplement Number 1

See the supplementary material for the computational details; electronic structure of the monolayered Ca(CoN)$_{2}$; total energy of the A-stacking and B-stacking categories of the Ca(CoN)$_{2}$ bilayer by omitting the influence of magnetic configurations; spin-resolved electronic structure of the A1 stacked bilayer with different magnetic order; total energy corresponding to different magnetic orders; band structures of the A2 and B2 stacked bilayer with different magnetic orders; AIMD results of the A2 and B4 stacked bilayer; spin-resolved band structures and atomic structures of four trilayer configurations; the band structures of the A2 stacked Ca(CoN)$_{2}$ bilayer with different magnetic orders obtained with/without SOC; spin-resolved electronic structure of the magnetic atoms of the A2 stacked bilayer with $M_{\downarrow\uparrow\downarrow\uparrow}$ and $M_{\downarrow\uparrow\uparrow\downarrow}$, respectively; plane-averaged charge density difference of the A2 stacking; plane-averaged charge density difference of the B4 stacking; band structure of the B4 stacked bilayer influenced by an external electric field; spin-resolved electronic structure of the B4 stacked bilayer with $M_{\downarrow\uparrow\downarrow\uparrow}$ and $M_{\downarrow\uparrow\uparrow\downarrow}$, respectively; Berry curvature distributions of the A2 stacked bilayer with $M_{\downarrow\uparrow\uparrow\downarrow}$ and the B4 stacked bilayer with $M_{\downarrow\uparrow\downarrow\uparrow}$, respectively.