Preparation and Characterization of High-Quality USb2 Thin Films on Graphene/6H-SiC(0001)

Heavy fermion systems can exhibit abundant attractive quantum ground states by tuning external parameters such as dimension. High-quality USb2 thin films were prepared on graphene/6H-SiC(0001) surface by molecule beam epitaxy. Combining the reflection high energy electron diffraction, X-ray diffraction, electric transport and X-ray photoelectron spectroscopy measurements, it is demonstrated that the grown USb2 films are high-quality single crystals. Furthermore, the surface topography, atomic structure and band structures of USb2 films were characterized by scanning tunneling microscopy (STM) and angle-resolved photoelectron spectroscopy (ARPES). Results show that the surface atomic structure, electric transport property and band structure of the grown USb2 films are similar to those of bulk USb2 single crystals. The preparation and characterization of high-quality USb2 films provide precious experimental experiences for exploring fantastic properties of low-dimensional uranium-based heavy fermion systems by growing ultrathin films with desirable thickness in the future.