Emergence of topological and trivial interface states in VSe₂ films coupled to Bi₂Se₃

Engineering fault-tolerant topological devices inevitably requires coupling topological materials with ordinary metal contacts, which can impact the functionality of a nanoscale device architecture used for manipulating spin information. While interfacing ordinary metals with the prototypical topological insulator Bi₂Se₃ could foster the long-range propagation of spin-polarized states, we report instead the emergence of both topological and trivial Rashba-type interface states in trivial metal VSe₂ films grown on Bi₂Se₃, all predominantly localized near the VSe₂/Bi₂Se₃ interface. Their strongly decaying spectral weights are unveiled through thickness-dependent angle-resolved photoemission, which are then well-reproduced by our first-principles model for the mixed system’s spectral function. Our findings not only underscore potential design constraints of spin-polarized states in real topological devices but also uncover further the possible hybridization interactions between trivial and nontrivial materials, while offering a new, unique approach for examining localized symmetry-protected states in hybrid structures.