Two-electron edge states in a double SSH-chain of quantum dots

Abstract

We study an interacting two-body model with adjustable spin tunneling in the context of the double SSH chains for a quantum dot system. We discovered that varying interaction strengths and spin tunneling significantly influence the properties of correlated edge states in the energy spectrum obtained through exact diagonalization. We observe that stronger interactions lead to longer decay lengths of these states. Conversely, the decay length decreases as the difference in intracell or intercell tunneling increases. Importantly, the decay length is strongly correlated with the dynamical behavior of two particles; specifically, an increase in decay length corresponds to a decrease in motion frequency. This conclusion is supported by the observation of the expectation value of coordinate operators of the particles.