Publications by authors named "N G Burdet"
In unconventional superconductors, coupled charge and lattice degrees of freedom can manifest in ordered phases of matter that are intertwined. In the cuprate family, fluctuating short-range charge correlations can coalesce into a longer-range charge density wave (CDW) order which is thought to intertwine with superconductivity, yet the nature of the interaction is still poorly understood. Here, by measuring subtle lattice fluctuations in underdoped YBaCuO on quasi-static timescales (thousands of seconds) through X-ray photon correlation spectroscopy, we report sensitivity to both superconductivity and CDW.
View Article and Find Full Text PDFUnderstanding the interplay between charge, nematic, and structural ordering tendencies in cuprate superconductors is critical to unraveling their complex phase diagram. Using pump-probe time-resolved resonant X-ray scattering on the (0 0 1) Bragg peak at the Cu [Formula: see text] and O [Formula: see text] resonances, we investigate nonequilibrium dynamics of [Formula: see text] nematic order and its association with both charge density wave (CDW) order and lattice dynamics in La[Formula: see text]Eu[Formula: see text]Sr[Formula: see text]CuO[Formula: see text]. The orbital selectivity of the resonant X-ray scattering cross-section allows nematicity dynamics associated with the planar O 2[Formula: see text] and Cu 3[Formula: see text] states to be distinguished from the response of anisotropic lattice distortions.
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- X-ray free electron lasers (XFELs) are revolutionizing research by allowing scientists to create new states of matter and observe atomic motion through precise x-ray pulse measurements over time.
- A new methodology has been developed that significantly improves efficiency in analyzing photon distributions, achieving faster processing times on both CPU and GPU hardware, while maintaining accuracy in low-contrast scenarios.
- This AI-assisted algorithm not only simplifies complex analyses but also paves the way for new experimental possibilities in x-ray coherence spectroscopy, expanding its applications in structural dynamics.
X-ray photon fluctuation spectroscopy using a two-pulse mode at the Linac Coherent Light Source has great potential for the study of quantum fluctuations in materials as it allows for exploration of low-energy physics. However, the complexity of the data analysis and interpretation still prevent recovering real-time results during an experiment, and can even complicate post-analysis processes. This is particularly true for high-spatial resolution applications using CCDs with small pixels, which can decrease the photon mapping accuracy resulting from the large electron cloud generation at the detector.
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- - The study utilized hard X-ray spectro-ptychography to map the cerium density and valence in platinum-supported cerium-zirconium oxide (Pt/CeZrO) catalyst particles of micrometer size.
- - Findings indicated multiple oxidation behaviors during the oxygen storage process of the cerium-zirconium oxide particles based on the correlation between cerium density and valence in the images obtained.
- - This innovative technique of ptychographic-XAFS enhances the ability to perform nanoscale chemical imaging and structural analysis of complex catalysts.