Correlated-hopping-induced topological order in an atomic mixture

The large majority of topological phases in one-dimensional many-body systems are known to be inherited from the corresponding single-particle Hamiltonian. In this work, we go beyond this assumption and find a new example of topological order induced through specific interaction couplings. Specifically, we consider a fermionic mixture where one component experiences a staggered on-site potential and it is coupled through density-dependent hopping interactions to the other fermionic component. Crucially, by varying the sign of the staggered potential, we show that this latter fermionic component can acquire topological properties. Due to matrix product state simulations, we prove this result both at equilibrium by extracting the behavior of correlation functions and in an out-of-equilibrium scheme by employing a Thouless charge pumping. Notably, we further discuss how our results can be probed in quantum simulators made up of ultracold atoms. Our results reveal an important and alternative mechanism that can give rise to topological order.