Prediction of Ideal Topological Semimetals with Triply Degenerate Points in NaCu${}_3$Te${}_2$ Family

Abstract

Triply degenerate points (TDPs) in band structure of a crystal can generate novel TDP fermions without high-energy counterparts. Although identifying ideal TDP semimetals, which host clean TDP fermions around the Fermi level ($E_F$) without coexisting of other quasiparticles, is critical to explore the intrinsic properties of this new fermion, it is still a big challenge and has not been achieved up to now. Here, we disclose an effective approach to search for ideal TDP semimetals via selective band crossing between antibonding $s$ and bonding $p$ orbitals along a line in the momentum space with $C_{3v}$ symmetry. Applying this approach, we have successfully identified the NaCu${}_3$Te${}_2$ family of compounds to be ideal TDP semimetals, where two and only two pairs of TDPs are located around the $E_F$. Moreover, we reveal an interesting mechanism to modulate energy splitting between a pair of TDPs, and illustrate the intrinsic features of TDP Fermi arcs in these ideal TDP semimetals.

9 pages, 4 figures

References in corpus (3)

• Computing topological invariants without inversion symmetry
• Prediction of triple point fermions in simple half-Heusler topological insulators
• Spin texture on the Fermi surface of tensile strained HgTe

Cited by in corpus (3)

• Impurity-induced triple point fermions in twisted bilayer graphene
• Symmetry driven topological phases in XAgBi (X=Ba,Sr): An Ab-initio hybrid functional calculations
• Transport evidence of triply degenerate nodal semimetal YRh6Ge4