Extended Data Figure 8: Magnetic interlayer coupling and single-ion anisotropy as a function of on-site Hubbard U in bulk Cr2Ge2Te6.
From: Discovery of intrinsic ferromagnetism in two-dimensional van der Waals crystals
Blue circles represent single-ion anisotropy, and the magnetic anisotropy is out-of-plane (negative single-ion anisotropy) for U > 0.2 eV. Red squares represent interlayer magnetic coupling, which is ferromagnetic (negative) for U < 1.7 eV. Bulk Cr2Ge2Te6 is a ferromagnet with an out-of-plane easy axis. Therefore, the range 0.2 eV < U < 1.7 eV (shaded area) could qualitatively reproduce the bulk magnetic property. We set U = 0.5 eV in the subsequent calculations, because the experimentally estimated single-ion anisotropy in the bulk is small.
