Fidelity susceptibility of Su-Schrieffer-Heeger model with further neighbour hopping term

Abstract

In this study, topological phase transition in Su-Schrieffer-Heeger (SSH) model with a further neighbour hopping term has been studied in terms of fidelity susceptibility. Topological phase transition point in the standard SSH model has been identified before by noting the divergence of fidelity susceptibility. The same approach has been employed here where fidelity susceptibility is found to diverge at the phase transition points. Additionally, effect of staggered potential on the fidelity susceptibility has been explored. Analytic expression for fidelity susceptibility has been obtained along with its numerical estimation on finite chains by exact diagonalization. Fidelity susceptibility exhibits sharp peaks at the phase transition points in both approaches. Scaling exponent of this divergence has been obtained numerically which is found to agree to that of the standard SSH model without further neighbour terms.