Charge order is universal among high-Tc cuprates but its relevance to superconductivity is not established. It is widely believed that, while static order competes with superconductivity, dynamic order may be favorable and even contribute to Cooper pairing. We use time-resolved resonant soft x-ray scattering to study the collective dynamics of the charge order in the prototypical cuprate, La2−xBaxCuO4. We find that, at energy scales 0.4 meV ≲ω≲2 meV, the excitations are overdamped and propagate via Brownian-like diffusion. At energy scales below 0.4 meV the charge order exhibits dynamic critical scaling, displaying universal behavior arising from propagation of topological defects. Our study implies that charge order is dynamic, so may participate tangibly in superconductivity.
@article{arxiv.1808.04847,
title = {Ultrafast time-resolved x-ray scattering reveals diffusive charge order dynamics in La$_{2-x}$Ba$_x$CuO$_4$},
author = {Matteo Mitrano and Sangjun Lee and Ali A. Husain and Luca Delacretaz and Minhui Zhu and Gilberto de la Peña Munoz and Stella Sun and Young Il Joe and Alexander H. Reid and Scott F. Wandel and Giacomo Coslovich and William Schlotter and Tim van Driel and John Schneeloch and Genda D. Gu and Sean Hartnoll and Nigel Goldenfeld and Peter Abbamonte},
journal= {arXiv preprint arXiv:1808.04847},
year = {2018}
}