▎ 摘　　要

The spin stiffness of the bilayer zigzag graphene nanoribbon for several configurations was obtained by means of the total energy difference of the flat spiral formations within the self-consistent calculation. To realize it, the penalty functional was employed to fix the direction of the magnetic moment of the carbon atom at the edges. Using the experimental lattice constant and the interlayer distance, the results showed that the total energy of each configuration is inversely proportional to the spin stiffness, which implies that the most stable configuration has the highest spin stiffness. For the final discussion, we also justified that the most stable configuration is not robust to the interlayer distance.