Non-trivial topology in rare-earth monopnictides from dimensionality reduction

Abstract

Thin films of rare-earth monopnictide semimetals are expected to turn into semiconductors due to quantum confinement effect, which lifts the overlap between electron pockets at Brillouin zone edges and hole pockets at the zone center. Instead, taking non-magnetic LaSb as an example, we find the emergence of a quantum spin Hall insulator phase in LaSb(001) films as the thickness is reduced to 7, 5, or 3 monolayers. This is attributed to a strong quantum confinement effect on the in-plane electron pockets, and the lack of quantum confinement on the out-of-plane pocket in reciprocal space projected onto zone center, leading to a band inversion. Spin-orbit coupling opens a sizeable non-trivial gap in the band structure of the thin films. Such effect is shown to be general in rare-earth monopnictides and may lead to interesting phenomena when coupled with the 4f magnetic moments present in other members of this family of materials.

References in corpus (16)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Topological Insulators with Inversion Symmetry
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
• Wannier representation of Z_2 topological insulators
• First Principles Calculations for Topological Quantum Materials
• Distinct Electronic Structure for the Extreme Magnetoresistance in YSb
• Evidence of topological insulator state in the semimetal LaBi
• Emergence of Fermi arcs and novel magnetic splitting in an antiferromagnet
• Local Density of States and Interface Effects in Semimetallic ErAs Nanoparticles Embedded in GaAs
• Rare-earth monopnoctides -- family of antiferromagnets hosting magnetic Fermi arcs
• Approaching a Minimal Topological Electronic Structure in Antiferromagnetic Topological Insulator MnBi2Te4 via Surface Modification
• Evolution of the electronic structure of ultrathin MnBi2Te4 Films
• Epitaxial growth, magnetoresistance, and electronic band structure of GdSb magnetic semimetal films
• Tuning the Band Topology of GdSb by Epitaxial Strain