Band Structure engineering in epitaxial LuSb thin films via dimensional confinement and bi-axial strain

Observation of extreme magnetoresistance (XMR) in rare-earth monopnictides has raised strong interest in understanding the role of its electronic structure. Here, the first demonstration of epitaxial synthesis of LuSb thin films on GaSb (001) substrates will be presented. Combining the techniques of molecular-beam epitaxy, low-temperature magnetotransport, angle-resolved photoemission spectroscopy, and hybrid density functional theory, we have unveiled the bandstructure of LuSb, where electron-hole compensation is identified as a mechanism responsible for XMR. However, by fabricating ultra-thin films, it is possible to controllably create an imbalance in the band fillings of electron and hole-like carriers in this otherwise compensated semimetal. Moreover, magnetoresistance behavior can also be tuned by application of bi-axial strain by synthesizing thin films of LuSb on lattice mis-matched substrates. Our work demonstrates the efficacy of epitaxial synthesis of rare-earth monopnictides to control its electronic structure, and thereby its physical properties