Probing symmetry protected topology in and out of equilibrium in an interacting SSH ladder

We study the effects of fermionic interactions on the symmetry-protected topology (SPT) of the Su–Schrieffer–Heeger model in a ladder geometry. This geometry induces symmetry-preserving interactions that leave the topological phase transition point intact while renormalizing the dimerization point. Through mean-field theory and tensor-network simulations, we characterize the ground state phase diagram of our model. We then show that quench dynamics reproduce the same phase diagram via time-averaged edge magnetization, thereby bridging equilibrium SPT physics with a dynamical probing scheme. Our findings highlight quench dynamics as a useful diagnostic for interacting topological matter.