An inelastic x-ray study of phonon broadening and charge density wave formation in ortho-II ordered YBa2Cu3O6.54

TL;DR

This study uses inelastic x-ray scattering to explore charge density wave formation and phonon behavior in underdoped YBa2Cu3O6.54, revealing static CDW order at low temperatures and phonon broadening near the CDW wavevector.

Contribution

It provides new insights into the static nature of CDW order and phonon anomalies in a high-temperature superconductor at specific temperatures.

Findings

CDW order is static below ~55 K

Phonons near the CDW wavevector show increased linewidths at low temperatures

Phonon anomalies occur well below the CDW onset temperature

Abstract

Inelastic x-ray scattering is used to investigate charge density wave (CDW) formation and the low-energy lattice dynamics of the underdoped high temperature superconductor ortho-II YBa2Cu3O6.54. We find that, for a temperature ~1/3 of the CDW onset temperature (~155 K), the CDW order is static within the resolution of the experiment, that is the inverse lifetime is less than 0.3 meV. In the same temperature region, low-energy phonons near the ordering wavevector of the CDW show large increases in their linewidths. This contrasts with the usual behavior in CDW systems where the phonon anomalies are strongest near the CDW onset temperature