Jump to main content
Jump to site search

Issue 12, 2017
Previous Article Next Article

Emergence of topological nodal loops in alkaline-earth hexaborides XB6 (X = Ca, Sr, and Ba) under pressure

Author affiliations

Abstract

Based on first-principles calculations, we report that external pressure can induce a topological phase transition in alkaline-earth hexaborides, XB6 (X = Ca, Sr, and Ba). It was revealed that XB6 are transformed from trivial semiconductors to topological node-line semimetals under moderate pressure when the spin–orbit coupling (SOC) is ignored. The band inversion between the B p-orbitals at the X point is responsible for the formation of node-line semimetals. Three node-line rings around the X point are protected by the combination of the time-reversal and spatial inversion symmetries, and drumhead surface bands are obtained in the interiors of the projected node-line rings. When the SOC is included, tiny gaps (<4.8 meV) open at the crossing lines and the XB6 become strong topological insulators with Z2 indices (1 : 111). As the SOC-induced gap opening is negligible, our findings thus suggest ideal real systems for experimental exploration of the fundamental physics of topological node-line semimetals.

Graphical abstract: Emergence of topological nodal loops in alkaline-earth hexaborides XB6 (X = Ca, Sr, and Ba) under pressure

Back to tab navigation

Supplementary files

Publication details

The article was received on 09 Dec 2016, accepted on 23 Feb 2017 and first published on 23 Feb 2017


Article type: Paper
DOI: 10.1039/C6CP08421D
Citation: Phys. Chem. Chem. Phys., 2017,19, 8210-8215
  •   Request permissions

    Emergence of topological nodal loops in alkaline-earth hexaborides XB6 (X = Ca, Sr, and Ba) under pressure

    L.-Y. Gan, R. Wang, Y. J. Jin, D. B. Ling, J. Z. Zhao, W. P. Xu, J. F. Liu and H. Xu, Phys. Chem. Chem. Phys., 2017, 19, 8210
    DOI: 10.1039/C6CP08421D

Search articles by author

Spotlight

Advertisements