Topological phases emerging from spin-orbital physics

We study the evolution of spin-orbital correlations in an inhomogeneous quantum system with an impurity replacing a doublon by a holon orbital degree of freedom. Spin-orbital entanglement is large when spin correlations are antiferromagnetic, while for a ferromagnetic host we obtain a chain with only orbital interactions. In this regime, the orbital model can be mapped on spin-less fermions and we uncover topological phases with zero energy modes at the edge or at the domain between magnetically inequivalent regions.