# Spin dynamics of edge-sharing spin chains in SrCa13Cu24O41

## TL;DR

This study investigates the magnetic excitations in highly Ca-doped SrCa13Cu24O41, revealing gapless spin waves with specific dispersions, and compares these findings to similar compounds to understand doping effects on spin dynamics.

## Contribution

The paper provides the first detailed inelastic neutron scattering analysis of SrCa13Cu24O41, showing a transition from gapped to gapless excitations due to hole transfer upon Ca doping.

## Key findings

- Gapless spin-wave excitations observed along a and c axes.
- Nearest-neighbour interaction Jc is 5.4 meV, interchain Ja is 4.4 meV.
- Transition from gapped to gapless excitations with Ca doping.

## Abstract

The low-energy magnetic excitation from the highly Ca-doped quasi-one-dimensional magnet SrCa13Cu24O41 was studied in the magnetic ordered state by using inelastic neutron scattering. We observed the gapless spin-wave excitation, dispersive along the a and c axes but nondispersive along the b axis. Such excitations are attributed to the spin wave from the spin-chain sublattice. Model fitting to the experimental data gives the nearest-neighbour interaction Jc as 5.4 meV and the interchain interaction Ja = 4.4 meV. Jc is antiferromagnetic and its value is close to the nearest-neighbour interactions of the similar edge-sharing spin-chain systems such as CuGeO3. Comparing with the hole-doped spin chains in Sr14Cu24O41, which shows a spin gap due to spin dimers formed around Zhang-Rice singlets, the chains in SrCa13Cu24O41 show a gapless excitation in this study. We ascribe such a change from gapped to gapless excitations to holes transferring away from the chain sublattice into the ladder sublattice upon Ca doping.

---
Source: https://tomesphere.com/paper/1901.02102