Evidence for the Coexistence of Dirac Surface States and Fermi Arc in a Quasi-1D Material

Searching for topological matter with multiple topological orders is of particular interest in the field of material science and condensed matter physics, due to the possible intertwined states and potential applications in low-dissipation spintronics. Herein, the single crystal samples of quasi-1D matter is synthesized, Ti₄FeBi₂, and electronic structure of (110) surface is characterized by using angle-resolved photoemission spectroscopy (ARPES) combined with the first-principle calculations. The Dirac cone states with the linear energy-momentum dispersion have been identified, which is evoked by the band inversion effect after taking the spin-orbit coupling into account. Moreover, the Fermi arcs connecting two bulk Dirac points are revealed by the comparative study between ARPES spectra and calculation results. The results not only indicate the dual topological orders in Ti₄FeBi₂ but also offer an ideal material platform for further research on the modulation of emerging physical states.