# Magnetic excitations and transport properties in frustrated ferromagnetic chain

## TL;DR

This study investigates spin transport in a frustrated ferromagnetic chain, revealing that magnetic field enhances spin transport via bound magnons, with implications for understanding spin nematic states.

## Contribution

It provides numerical evidence that magnetic field increases spin Drude weight in a frustrated chain, highlighting the role of bound magnons in spin transport.

## Key findings

- Spin Drude weight is zero at zero magnetic field, indicating diffusive transport.
- Magnetic field enhances the spin Drude weight at low temperatures.
- Bound magnons contribute significantly to spin transport under magnetic field.

## Abstract

To clarify the transport property mediated by bound magnons in a spin nematic state, we investigate the spin Drude weight of a spin-1/2 $J_{1}$-$J_{2}$ Heisenberg chain with ferromagnetic $J_{1}$ and antiferromagnetic $J_{2}$ in a magnetic field by numerical diagonalization. At zero magnetic field, numerical results with up to 24 sites suggest that the spin Drude weight would be zero in the thermodynamic limit, indicating diffusive spin transport. With increasing the magnetic field, the spin Drude weight is enhanced at low temperatures, indicating that bound magnons would contribute to the spin transport.