Edge states of Spin-1/2 Two-Leg Ladder with Four-Spin Ring Exchange

TL;DR

This paper investigates the edge states and entanglement properties of a spin-1/2 two-leg ladder with four-spin ring exchange, revealing insights into its topological and gapped spin liquid phases.

Contribution

It introduces a novel analysis of edge states and entanglement entropy in the vector chirality phase of the ladder system, linking boundary phenomena to bulk topological properties.

Findings

Edge states characterize the gapped bulk spin liquid.

Entanglement entropy reveals topological features.

Edge states serve as indicators of the phase's topological nature.

Abstract

A topological insulator and its spin analogue as a gapped spin liquid have characteristic low energy excitations (edge states) within the gap when the systems have boundaries. This is the bulk-edge correspondence, which implies that the edge states themselves characterize the gapped bulk spin liquid. Based on the general principle, we analyzed the vector chirality phase of the spin-1/2 ladder with ring exchange by using the edge states and the entanglement entropy.