Quenched dynamics and spin-charge separation in an interacting topological lattice

TL;DR

This paper investigates the interplay of topology, interactions, and dynamics in a one-dimensional fermionic lattice, revealing entangled edge modes, spin-charge separation, and correlation spreading under quenched conditions.

Contribution

It provides new insights into how interactions affect topological edge modes and demonstrates the potential for observing spin-charge separation in such systems.

Findings

Edge modes depend on interaction sign, showing particles of opposite spin or pairs and holons.

Strong entanglement exists between system edges, affecting correlation dynamics.

Correlation functions propagate within the light-cone, revealing non-trivial dynamics.

Abstract

We analyze the static and dynamical properties of a one-dimensional topological lattice, the fermionic Su-Schrieffer-Heeger model, in the presence of on-site interactions. Based on a study of charge and spin correlation functions, we elucidate the nature of the topological edge modes, which depending on the sign of the interactions, either display particles of opposite spin on opposite edges, or a pair and a holon. This study of correlation functions also highlights the strong entanglement that exists between the opposite edges of the system. This last feature has remarkable consequences upon subjecting the system to a quench, where an instantaneous edge-to-edge signal appears in the correlation functions characterizing the edge modes. Besides, other correlation functions are shown to propagate in the bulk according to the light-cone imposed by the Lieb-Robinson bound. Our study reveals how one-dimensional lattices exhibiting entangled topological edge modes allow for a non-trivial correlation spreading, while providing an accessible platform to detect spin-charge separation using state-of-the-art experimental techniques.