Light-enhanced Charge Density Wave Coherence in a High-Temperature Superconductor

Wandel S, Boschini F, da Silva Neto EH, Shen L, Na MX, Zohar S, Wang Y, Welch GB, Seaberg MH, Koralek JD, Dakovski GL, Hettel W, Lin M-F, Moeller SP, Schlotter WF, Reid AH, Minitti MP, Boyle T, He F, Sutarto R, Liang R, Bonn D, Hardy W, Kaindl RA, Hawthorn DG, Lee J-S, Kemper AF, Damascelli A, Giannetti C, Turner JJ, Coslovich G
Science 376, 6595 (2022)


In high-TC cuprates, superconductivity and charge density waves (CDW) are competitive, yet coexisting orders. To understand their microscopic interdependence a probe capable of discerning their interaction on its natural length and time scales is necessary. Here we use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBa2Cu3O6+x following the quench of superconductivity by an infrared laser pulse. We observe a picosecond non-thermal response of the CDW order, characterized by a large enhancement of spatial coherence, nearly doubling the CDW correlation length, while only marginally affecting its amplitude. This ultrafast snapshot of the interaction between order parameters demonstrates that their competition manifests inhomogeneously through disruption of spatial coherence, and indicates the role of superconductivity in stabilizing topological defects within CDW domains.