Abstract

Generally, the topological corner state in two-dimensional (2D) second-order topological insulator (SOTI) is equivalent to the well-known domain wall state, which is originated from the mass-inversion between two adjacent edges with phase shift of π. In this work, go beyond this conventional physical picture, we report a fractional mass-kink induced 2D SOTI in monolayer FeSe with canted checkerboard antiferromagnetic (AFM) order by analytic model and first-principles calculations. The canted spin associated in-plane Zeeman field can gap out the quantum spin Hall edge state of FeSe, forming a fractional mass-kink with phase shift of π/2 at the rectangular corner, and generating an in-gap topological corner state with fractional charge of e/4. Moreover, the topological corner state is robust to a finite perturbation, existing in both naturally and non-naturally cleaved corners, regardless of the edge orientation. Our results not only demonstrate a material system to realize the unique 2D AFM SOTI, but also pave a way to design the higher-order topological states from fractional mass-kink with arbitrary phase shift.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.