Cluster- and energy-separated extreme states in a synthesized superatomic solid

Compared with conventional atomic crystals, superatomic solids are more attractive for providing opportunities to generate unexpected emergent states associated with their unique hierarchical structure. Using first-principles calculations, herein, we identify two cluster- and energy-separated extreme states in a synthesized binary fulleride. An emergent superatomic Dirac state and a flat band with extreme effective mass are found on different sides of the Fermi level, which are separately contributed by different constituent clusters. The coexistence of Dirac and flat states in a semiconductor rather than a metal/semimetal may open a door for constructing Dirac field-effect devices, giving rise to ultrafast Dirac carrier transport.