Lattice distortion induced first- and second-order topological phase transition in a rectangular high- T c superconducting monolayer

The authors show that in the FeSe${}_{x}$Te${}_{1\ensuremath{-}x}$ monolayer with rectangular crystal structure, the lattice distortion can induce the first-order topological phase transition of the electronic band structure and the second-order phase transition of the superconductor in a wide doping range.