Abstract
We report an inelastic neutron scattering study of acoustic phonons in the charge and orbitally ordered bilayer manganite . For excitation energies less than 15 meV, we observe an abrupt increase (decrease) of the phonon energies (linewidths) of a transverse acoustic phonon branch at , , upon entering the low temperature charge and orbital ordered state (). This indicates a reduced electron-phonon coupling due to a decrease of electronic states at the Fermi level leading to a partial removal of the Fermi surface below and provides direct experimental evidence for a link between electron-phonon coupling and charge order in manganites.
- Received 27 May 2011
DOI:https://doi.org/10.1103/PhysRevLett.107.207202
© 2011 American Physical Society