Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA.
Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
Science. 2022 May 20;376(6595):860-864. doi: 10.1126/science.abd7213. Epub 2022 May 19.
Superconductivity and charge density waves (CDWs) are competitive, yet coexisting, orders in cuprate superconductors. To understand their microscopic interdependence, a probe capable of discerning their interaction on its natural length and time scale is necessary. We use ultrafast resonant soft x-ray scattering to track the transient evolution of CDW correlations in YBaCuO after the quench of superconductivity by an infrared laser pulse. We observe a nonthermal response of the CDW order characterized by a near doubling of the correlation length within ≈1 picosecond of the superconducting quench. Our results are consistent with a model in which the interaction between superconductivity and CDWs manifests inhomogeneously through disruption of spatial coherence, with superconductivity playing the dominant role in stabilizing CDW topological defects, such as discommensurations.
超导性和电荷密度波 (CDW) 是竞争的，但共存的，在铜酸盐超导体中的有序状态。为了理解它们的微观相互依存关系，需要一种能够在其自然长度和时间尺度上辨别它们相互作用的探针。我们使用超快共振软 X 射线散射来跟踪 YBaCuO 中 CDW 相关性在红外激光脉冲猝灭超导性后的瞬态演化。我们观察到 CDW 有序的非热响应，其特征是在超导猝灭后的约 1 皮秒内，相关长度几乎增加了一倍。我们的结果与一个模型一致，即超导性和 CDW 之间的相互作用通过空间相干性的破坏表现出非均匀性，超导性在稳定 CDW 拓扑缺陷（如失谐）方面起着主导作用。
