2017/04/03 by Mighfar Imam, Abhishek Kumar Singh, Imam, Mighfar +1
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Graphene research and applications #Heusler alloys: electronic and magnetic properties #Materials Science (cond-mat.mtrl-sci) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.1704.00697
openalex publication_date 2017/04/03 · openalex created_date 2017/04/14 · openalex updated_date 2026/07/28
Based on first-principles study, we report the finding of a new topological semimetal LiBaBi in half-Heusler phase. The remarkable feature of this nonmagnetic, inversion-symmetry-breaking material is that it consists of only simple s- and p-block elements. Interestingly, the material is ordinary insulator in the absence of spin-orbit coupling (SOC) and becomes nodal-surface topological semimetal showing drumhead states when SOC is included. This is in stark contrast to other nodal-line and nodal-surface semimetals, where the extended nodal structure is destroyed once SOC is included. Importantly, the linear band crossings host three-, four-, five- and six-fold degeneracies near the Fermi level, making this compound very attractive for the study of `unconventional' fermions. The band crossing points form a three-dimensional nodal structure around the zone center at the Fermi level. We identify the surface states responsible for the appearance of the drumhead states. The alloy also shows a phase transition from topological semimetal to a trivial insulator on application of pressure. In addition to revealing an intriguing effect of SOC on the nodal structure, our findings introduce a new half-Heusler alloy in the family of topological semimetals, thus creating more avenues for experimental exploration.