In situ engineering and characterization on the artificial heterostructures of correlated materials with integrated OMBE–ARPES

The combination of oxide molecular beam epitaxy (OMBE) and angle resolved photoemission spectroscopy (ARPES) opens a new field for studying correlated electron systems. The in situ growth of single crystalline films by OMBE increases the variety of materials available for ARPES study. Investigating the electronic structure of thin films by ARPES deepens our understanding on the interaction of different degrees of freedom at thin films and interfaces. In this paper, we review the key elements of the integrated OMBE–ARPES technique and some representative works, including the in situ ARPES investigations on thin films with cubic perovskite structure, ultra-thin films with thickness dependent metal–insulator transition, the composition and strain dependence of interfacial superconductivity, and correlated behavior in superlattices. These examples illustrate the new opportunities brought by integrating OMBE and ARPES on exploring novel physical states and functional materials.