Abstract
We study theoretically the interplay effect of Zeeman field and modulated spin-orbit coupling on the topological properties of a one-dimensional dimerized lattice, known as Su-Schrieffer-Heeger model. We find that in the weak (strong) modulated spin-orbit coupling regime, trivial regions or nontrivial ones with two pairs of zero-energy states can be turned into nontrivial regions by applying a uniform (staggered) perpendicular Zeeman field through a topological phase transition. Furthermore, the resulting nontrivial phase hosting a pair of zero-energy boundary states can survive within a certain range of the perpendicular Zeeman field magnitude. Due to the effective time-reversal, particle-hole, chiral, and inversion symmetries, in the presence of either a uniform or a staggered perpendicular Zeeman field, the topological class of the system is BDI, which can be characterized by index. We also examine the robustness of the nontrivial phase by breaking the underlying symmetries, which results in that inversion symmetry plays an important role.
- Received 13 March 2016
- Revised 25 July 2016
DOI:https://doi.org/10.1103/PhysRevB.94.125119
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