Abstract:
A fractal structure in which a fractal dimension featuring the self-similarity is formed of mutually different two regions and which has at least one heterojunction. Particularly, in a star-shaped fractal structure, a heterojunction is formed by forming a region (dendritic region) having a low fractal dimension around a nucleus (somatic region) having a high fractal dimension. The phases of the two regions forming the heterojunction are mutually different ones, for example, a ferromagnetic phase and a paramagnetic phase or a metallic phase and a Mott-insulating phase. By using the fractal structure, a functional material or a functional device is realized.