# Correlation functions and excitation spectrum of the frustrated ferromagnetic spin-1/2 chain in an external magnetic field

## TL;DR

This paper investigates how magnetic fields influence the ground state and excitation spectrum of a one-dimensional frustrated ferromagnetic spin-1/2 chain, revealing a transition from spin-density-wave to nematic-like phases.

## Contribution

It combines effective field theory with numerical methods to analyze phase transitions and excitation gaps in the frustrated ferromagnetic chain under magnetic fields.

## Key findings

- Ground state transitions from spin-density-wave to nematic-like phase.
- Detailed analysis of the single spin-flip excitation gap.
- Finite-size corrections to excitation spectrum behavior.

## Abstract

Magnetic field effects on the one-dimensional frustrated ferromagnetic chain are studied by means of effective field theory approaches in combination with numerical calculations utilizing Lanczos diagonalization and the density matrix renormalization group method. The nature of the ground state is shown to change from a spin-density-wave region to a nematic-like one upon approaching the saturation magnetization. The excitation spectrum is analyzed and the behavior of the single spin-flip excitation gap is studied in detail, including the emergent finite-size corrections.