Higher-order topological Dirac phase in Y3InC: A First-principles study

SREEPARVATHY PUTHIYA COVILAKAM^1,2*, Rovi Angelo B. Villaos¹, Zhi-Quan Huang¹, Feng-Chuan Chuang^1,2,3,4

¹Physics, National Sun Yat-sen university, Kaohsiung, Taiwan
²Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan
³Center for Theoretical and Computational Physics, National Sun Yat-sen University, Kaohsiung, Taiwan
⁴Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:SREEPARVATHY PUTHIYA COVILAKAM, email:sree89parvathy@gmail.com

Recent research on higher-order topological insulators (HOTIs) has expanded our understanding of bulk-boundary correspondence by highlighting topologically protected hinge and corner states as their key features. These materials are characterized by gapless hinge states within the gapped bulk and surface states. Interestingly, current studies have extended the bulk-boundary correspondence to gapless Dirac phases, exhibiting the simultaneous existence of surface and hinge states. In this study, we introduce the bulk Y3InC and some members of the cubic antiperovskite family as promising candidates hosting a higher-order Dirac phase with hinge states. Band structure calculations under the hybrid functional approach showed the presence of twin Dirac points at symmetry-protected triple points attributed to spin-orbit coupling. The Z4 topological invariant and mirror Chern number showed the higher-order topological phase in these materials. To verify the existence of gapless hinge states, we conduct edge state calculations using a rod-shaped geometry of Y3InC. These results lay the groundwork for further experimental and theoretical investigations into cubic antiperovskite materials for higher-order topological phases.

Keywords: Higher-order topological Dirac phase , Antiperovskite materials , Hinge states , Multiple Dirac nodes , First-principles calculations