Z${}_2$ nontrivial topology of rare-earth binary oxide superconductor

Abstract

Recently, superconductivity has been discovered in rock-salt structured binary lanthanum monoxide LaO through state-of-the-art oxide thin-film epitaxy. In this work, we reveal that the normal state of superconducting LaO is a $Z_2$ nontrivial topological metal, where the Dirac point protected by the crystal symmetry is located around the Fermi energy. By analysing the orbital characteristics, we show that the nature of the topological band structure of LaO originates from the intra-atomic transition from the outer shell La 5$d$ to the inner shell 4$f$ orbitals driven by the strong octahedral crystal-field. Furthermore, the appearance of novel surface states unambiguously demonstrates the topological signature of LaO superconductor. Our theoretical findings not only shed new light into the understanding of the exotic quantum behaviors in LaO superconductor with intimate correlation between 4$f$ and 5$d$ orbitals in La, but also provide an exciting platform to explore the interplay between nontrivial topology and superconductivity.

6 pages, 4 figures, 1 table

References in corpus (14)

• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Insulators with Inversion Symmetry
• Topological Crystalline Insulators
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Three dimensional topological invariants for time reversal invariant Hamiltonians and the three dimensional quantum spin Hall effect
• Dirac materials
• Superconductivity in the ${\mathbb{Z}}_2$ kagome metal KV${}_3$Sb${}_5$
• Correlated Topological Insulators with Mixed Valence
• Size Effects on Transport Properties in Topological Anderson Insulators
• First-principles study of the superconductivity in LaO
• SmO thin films: a flexible route to correlated flat bands with nontrivial topology
• Evidence the ferromagnetic order on CoSb layer of LaCoSb${}_2$
• Pairing symmetry in monolayer of orthorhombic CoSb

Cited by in corpus (4)

• Reactive pulsed direct current magnetron sputtering deposition of semiconducting yttrium oxide thin film in ultralow oxygen atmosphere: A spectroscopic and structural investigation of growth dynamics
• Density Functional Theory Study of Lanthanide Monoxides under High Pressure: Pressure-Induced B1-B2 Transition
• Rocksalt rare-earth monoxides as electronic and magnetic materials
• Fidelity and variability in the interlayer electronic structure of the kagome superconductor CsV3Sb5