SmO thin films: a flexible route to correlated flat bands with nontrivial topology

Abstract

Using density functional theory based calculations, we show that the correlated mixed-valent compound SmO is a 3D strongly topological semi-metal as a result of a 4$f$-5$d$ band inversion at the X point. The [001] surface Bloch spectral density reveals two weakly interacting Dirac cones that are quasi-degenerate at the M_bar-point and another single Dirac cone at the Gamma_bar-point. We also show that the topological non-triviality in SmO is very robust and prevails for a wide range of lattice parameters, making it an ideal candidate to investigate topological nontrivial correlated flat bands in thin-film form. Moreover, the electron filling is tunable by strain. In addition, we find conditions for which the inversion is of the 4f-6s type, making SmO to be a rather unique system. The similarities of the crystal symmetry and the lattice constant of SmO to the well studied ferromagnetic semiconductor EuO, makes SmO/EuO thin film interfaces an excellent contender towards realizing the quantum anomalous Hall effect in a strongly correlated electron system.

arXiv commentPaper+supplement

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Cited by in corpus (9)

• Electronic structure of YbB${}_6$: Is it a Topological Insulator or not?
• Bulk and surface electronic properties of SmB6: a hard x-ray photoelectron spectroscopy study
• Coexistence of Weyl semimetal and Weyl nodal loop semimetal phases in a collinear antiferromagnet
• Z${}_2$ nontrivial topology of rare-earth binary oxide superconductor
• Multiple topological Dirac cones in a mixed-valent Kondo semimetal: g-SmS
• Hard and soft x-ray photoemission spectroscopy study of the new Kondo system SmO thin film
• Valence state of Sm in single crystalline EuO thin films
• Rocksalt rare-earth monoxides as electronic and magnetic materials
• Anomalous 4$f$ fine structure in TmSe${}_{1-x}$Te${}_x$ across the metal-insulator transition