Re-entrant topological order in strongly correlated nanowire due to Rashba spin-orbit coupling

The effect of the Rashba spin orbit coupling (RSOC) on the topological properties of the one-dimensional (1D) extended \emph{s}-wave superconducting Hamiltonian, in the presence of strong electron-electron correlation, is investigated. It is found that a non-zero RSOC increases the periodicity of the effective Hamiltonian, which results in the folding of the Brillouin zone (BZ), and consequently in the emergence of an energy gap at the boundary of the BZ. If the chemical potential is inside the energy gap and it does not perceive the two-band structure of the resulting energy spectrum the topological phase is removed from the phase diagram.In contrast, if we move the chemical potential upwards towards the highest occupied band the opposite happens and the non-trivial topology is restored. This is the origin of re-entrant nature of the existent topological properties. This property of the system allows us to drive the system in and out of the topological phase only by the proper tuning of the chemical potential. A heterostructure involving van der Waals materials and a 1D Moire pattern for an investigation of the predicted effect has also been proposed and discussed in our work.
Comment: 7 pages (Main text), 6 figures, To be submitted to PRB