# Emergent incommensurate correlations in the frustrated ferromagnetic spin-1 chains

## TL;DR

This paper investigates frustrated ferromagnetic spin-1 chains, revealing incommensurate correlations and phase transitions using density matrix renormalization group methods, and compares findings with spin-1/2 and classical systems.

## Contribution

It uncovers the emergence of incommensurate correlations in the double Haldane phase of spin-1 chains due to ferromagnetic coupling, a novel insight into their phase behavior.

## Key findings

- Incommensurate correlations appear in the double Haldane phase.
- Short-range correlations evolve into ferromagnetic instability.
- Comparison with spin-1/2 and classical systems highlights unique quantum effects.

## Abstract

We study the frustrated ferromagnetic spin-1 chains, where the ferromagnetic nearest-neighbor coupling competes with the antiferromagnetic next-nearest-neighbor coupling. We use the density matrix renormalization group to obtain the ground states. Through the analysis of spin-spin correlations we identify the double Haldane phase as well as the ferromagnetic phase. It is shown that the ferromagnetic coupling leads to incommensurate correlations in the double Haldane phase. Such short-range correlations transform continuously into the ferromagnetic instability at the transition to the ferromagnetic phase. We also compare the results with the spin-1/2 and classical spin systems, and discuss the string orders in the system.