Structural Dynamics-Us最新文献_第8页

Ultrafast-induced coherent acoustic phonons in the two-dimensional magnet CrSBr. 二维磁体 CrSBr 中的超快诱导相干声子。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-03-20 eCollection Date: 2025-03-01 DOI: 10.1063/4.0000266

Jayajeewana N Ranhili, Sumit Khadka, Junjie Li, John Cenker, Alberto M Ruiz, Andrei Shumilin, José J Baldoví, Ka Shen, Mikhail Fedurin, Mark Palmer, Daniel G Chica, Paul Byaruhanga, Shuo Chen, Xiaodong Xu, Xavier Roy, Byron Freelon

{"title":"Ultrafast-induced coherent acoustic phonons in the two-dimensional magnet CrSBr.","authors":"Jayajeewana N Ranhili, Sumit Khadka, Junjie Li, John Cenker, Alberto M Ruiz, Andrei Shumilin, José J Baldoví, Ka Shen, Mikhail Fedurin, Mark Palmer, Daniel G Chica, Paul Byaruhanga, Shuo Chen, Xiaodong Xu, Xavier Roy, Byron Freelon","doi":"10.1063/4.0000266","DOIUrl":"10.1063/4.0000266","url":null,"abstract":"Magnetism in two-dimensional (2D) van der Waals (vdW) crystals offers promising new directions for low-dimensional physics and devices. In this work, mega-electron volt (MeV) ultrafast electron diffraction was employed to investigate the ultrafast atomic dynamics of a novel, 2D vdW magnetic single-crystal CrSBr. Femtosecond (fs) optical pump pulses excited non-equilibrium atomic displacements shown to be coherent acoustic phonons (CAPs). Phonon frequencies were extracted by analyzing oscillations of different Bragg peak (BP) intensities and were determined to be GHz acoustic disturbances that propagated as strain waves. Phonon modes exhibit anisotropy with respect to the a and b crystal axes. Subharmonic phonon frequencies were also observed, and this provided a signature of nonlinear oscillatory coupling between the laser-induced pumping phonon frequency and secondary phonon frequencies. Thus, CrSBr was found to serve as a nonlinear phononic frequency converter. The ultrafast time dependence of the Bragg intensity was simulated by incorporating an oscillating deviation parameter ansatz into expressions for the dynamical scattering intensity yielded excellent modeling of the ultrafast structural dynamics of the photo-excited 2D crystal. Our work provides a foundation for exploring how fs light pulses can influence phonon dynamics in materials with strong spin-lattice coupling. These results suggest that CAPs can match the magnon frequencies and show the promise of CrSBr for use in optical-to-microwave transducers and phononic devices.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"12 2","pages":"024501"},"PeriodicalIF":2.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11928097/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143694050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Implementation and performance of a fiber-coupled CMOS camera in an ultrafast reflective high-energy electron diffraction experiment. 光纤耦合CMOS相机在超快反射高能电子衍射实验中的实现与性能。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-03-06 eCollection Date: 2025-03-01 DOI: 10.1063/4.0000284

Jonas D Fortmann, Alexander Kaßen, Christian Brand, Thomas Duden, Michael Horn-von Hoegen

{"title":"Implementation and performance of a fiber-coupled CMOS camera in an ultrafast reflective high-energy electron diffraction experiment.","authors":"Jonas D Fortmann, Alexander Kaßen, Christian Brand, Thomas Duden, Michael Horn-von Hoegen","doi":"10.1063/4.0000284","DOIUrl":"10.1063/4.0000284","url":null,"abstract":"The implementation of a monolithic fiber-optically coupled CMOS-based TemCam-XF416 camera into our ultra-high vacuum (UHV) ultrafast reflection high-energy electron diffraction setup is reported. A combination of a pumpable gate valve and a self-built cooling collar allows UHV conditions to be reached without the need to remove the heat-sensitive device. The water-cooled collar is mounted to the camera housing and prevents heating of the camera upon bakeout of the UHV chamber. The TemCam possesses an one order of magnitude higher spatial resolution, which provides 30% higher resolution in reciprocal space than the previously used microchannel plate detector. The low background intensity and the four times larger dynamic range enable analysis of the diffuse intensity of the diffraction pattern like Kikuchi lines and bands. A key advantage over the previous MCP detector is the complete absence of the blooming effect, which enables the quantitative spot profile analysis of the diffraction spots. The inherent light sensitivity in an optical pump experiment can be overcome by subtracting a pump image without a probe, using photons with <math><mrow><mi>h</mi> <mi>ν</mi> <mo><</mo> <mn>1.12</mn></mrow> </math> eV (indirect bandgap of silicon), or shielding any stray light.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"12 2","pages":"024301"},"PeriodicalIF":2.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11888785/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143587659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sharing our excitement for structural science through mentorship. 通过指导分享我们对结构科学的兴奋。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-02-10 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000285

Gerald F Audette

引用次数: 0

Time-resolved x-ray absorption spectroscopy probe in ultrafast surface chemistry. 超快表面化学中时间分辨x射线吸收光谱探针。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-02-05 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000289

Anders Nilsson

引用次数: 0

Whither the protein landscape? 蛋白质的前景在哪里？

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-02-05 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000291

Charles W Carter, George N Phillips

引用次数: 0

Non-equilibrium states and interactions in the topological insulator and topological crystalline insulator phases of NaCd₄As₃. NaCd4As3拓扑绝缘体和拓扑晶体绝缘体相的非平衡态及其相互作用。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-02-05 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000273

Tika R Kafle, Yingchao Zhang, Yi-Yan Wang, Xun Shi, Na Li, Richa Sapkota, Jeremy Thurston, Wenjing You, Shunye Gao, Qingxin Dong, Kai Rossnagel, Gen-Fu Chen, James Freericks, Henry C Kapteyn, Margaret M Murnane

{"title":"Non-equilibrium states and interactions in the topological insulator and topological crystalline insulator phases of NaCd4As3.","authors":"Tika R Kafle, Yingchao Zhang, Yi-Yan Wang, Xun Shi, Na Li, Richa Sapkota, Jeremy Thurston, Wenjing You, Shunye Gao, Qingxin Dong, Kai Rossnagel, Gen-Fu Chen, James Freericks, Henry C Kapteyn, Margaret M Murnane","doi":"10.1063/4.0000273","DOIUrl":"10.1063/4.0000273","url":null,"abstract":"Topological materials are of great interest because they can support metallic edge or surface states that are robust against perturbations, with the potential for technological applications. Here, we experimentally explore the light-induced non-equilibrium properties of two distinct topological phases in NaCd4As3: a topological crystalline insulator (TCI) phase and a topological insulator (TI) phase. This material has surface states that are protected by mirror symmetry in the TCI phase at room temperature, while it undergoes a structural phase transition to a TI phase below 200 K. After exciting the TI phase by an ultrafast laser pulse, we observe a leading band edge shift of >150 meV that slowly builds up and reaches a maximum after ∼0.6 ps and that persists for ∼8 ps. The slow rise time of the excited electron population and electron temperature suggests that the electronic and structural orders are strongly coupled in this TI phase. It also suggests that the directly excited electronic states and the probed electronic states are weakly coupled. Both couplings are likely due to a partial relaxation of the lattice distortion, which is known to be associated with the TI phase. In contrast, no distinct excited state is observed in the TCI phase immediately or after photoexcitation, which we attribute to the low density of states and phase space available near the Fermi level. Our results show how ultrafast laser excitation can reveal the distinct excited states and interactions in phase-rich topological materials.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"12 1","pages":"014501"},"PeriodicalIF":2.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11811906/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143400393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Filling data analysis gaps in time-resolved crystallography by machine learning. 用机器学习填补时间分辨晶体学的数据分析空白。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-01-21 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000280

Justin Trujillo, Russell Fung, Madan Kumar Shankar, Peter Schwander, Ahmad Hosseinizadeh

{"title":"Filling data analysis gaps in time-resolved crystallography by machine learning.","authors":"Justin Trujillo, Russell Fung, Madan Kumar Shankar, Peter Schwander, Ahmad Hosseinizadeh","doi":"10.1063/4.0000280","DOIUrl":"10.1063/4.0000280","url":null,"abstract":"There is a growing understanding of the structural dynamics of biological molecules fueled by x-ray crystallography experiments. Time-resolved serial femtosecond crystallography (TR-SFX) with x-ray Free Electron Lasers allows the measurement of ultrafast structural changes in proteins. Nevertheless, this technique comes with some limitations. One major challenge is the quality of data from TR-SFX measurements, which often faces issues like data sparsity, partial recording of Bragg reflections, timing errors, and pixel noise. To overcome these difficulties, conventionally, large volumes of data are collected and grouped into a few temporal bins. The data in each bin are then averaged and paired with the mean of their corresponding jittered timestamps. This procedure provides one structure per bin, resulting in a limited number of averaged structures for the entire time interval spanned by the experiment. Therefore, the information on ultrafast structural dynamics at high temporal resolution is lost. This has initiated research for advanced methods of analyzing experimental TR-SFX data beyond the standard binning and averaging method. To address this problem, we use a machine learning algorithm called Nonlinear Laplacian Spectral Analysis (NLSA), which has emerged as a promising technique for studying the dynamics of complex systems. In this work, we demonstrate the power of this algorithm using synthetic x-ray diffraction snapshots from a protein with significant data incompleteness, timing uncertainties, and noise. Our study confirms that NLSA is a suitable approach that effectively mitigates the effects of these artifacts in TR-SFX data and recovers accurate structural dynamics information hidden in such data.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"12 1","pages":"014101"},"PeriodicalIF":2.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11758283/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Convergent-beam attosecond x-ray crystallography. 会聚束阿秒x射线晶体学。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2025-01-09 eCollection Date: 2025-01-01 DOI: 10.1063/4.0000275

Henry N Chapman, Chufeng Li, Saša Bajt, Mansi Butola, J Lukas Dresselhaus, Dmitry Egorov, Holger Fleckenstein, Nikolay Ivanov, Antonia Kiene, Bjarne Klopprogge, Viviane Kremling, Philipp Middendorf, Dominik Oberthuer, Mauro Prasciolu, T Emilie S Scheer, Janina Sprenger, Jia Chyi Wong, Oleksandr Yefanov, Margarita Zakharova, Wenhui Zhang

{"title":"Convergent-beam attosecond x-ray crystallography.","authors":"Henry N Chapman, Chufeng Li, Saša Bajt, Mansi Butola, J Lukas Dresselhaus, Dmitry Egorov, Holger Fleckenstein, Nikolay Ivanov, Antonia Kiene, Bjarne Klopprogge, Viviane Kremling, Philipp Middendorf, Dominik Oberthuer, Mauro Prasciolu, T Emilie S Scheer, Janina Sprenger, Jia Chyi Wong, Oleksandr Yefanov, Margarita Zakharova, Wenhui Zhang","doi":"10.1063/4.0000275","DOIUrl":"10.1063/4.0000275","url":null,"abstract":"Sub-ångström spatial resolution of electron density coupled with sub-femtosecond to few-femtosecond temporal resolution is required to directly observe the dynamics of the electronic structure of a molecule after photoinitiation or some other ultrafast perturbation, such as by soft X-rays. Meeting this challenge, pushing the field of quantum crystallography to attosecond timescales, would bring insights into how the electronic and nuclear degrees of freedom couple, enable the study of quantum coherences involved in molecular dynamics, and ultimately enable these dynamics to be controlled. Here, we propose to reach this realm by employing convergent-beam x-ray crystallography with high-power attosecond pulses from a hard-x-ray free-electron laser. We show that with dispersive optics, such as multilayer Laue lenses of high numerical aperture, it becomes possible to encode time into the resulting diffraction pattern with deep sub-femtosecond precision. Each snapshot diffraction pattern consists of Bragg streaks that can be mapped back to arrival times and positions of X-rays on the face of a crystal. This can span tens of femtoseconds and can be finely sampled as we demonstrate experimentally. The approach brings several other advantages, such as an increase in the number of observable reflections in a snapshot diffraction pattern, all fully integrated, to improve the speed and accuracy of serial crystallography-especially for crystals of small molecules.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"12 1","pages":"014301"},"PeriodicalIF":2.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731522/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143014605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Integrated edge-to-exascale workflow for real-time steering in neutron scattering experiments. 用于中子散射实验实时转向的从边缘到超大规模的集成工作流程。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2024-12-24 eCollection Date: 2024-11-01 DOI: 10.1063/4.0000279

Junqi Yin, Viktor Reshniak, Siyan Liu, Guannan Zhang, Xiaoping Wang, Zhongcan Xiao, Zachary Morgan, Sylwia Pawledzio, Thomas Proffen, Christina Hoffmann, Huibo Cao, Bryan C Chakoumakos, Yaohua Liu

{"title":"Integrated edge-to-exascale workflow for real-time steering in neutron scattering experiments.","authors":"Junqi Yin, Viktor Reshniak, Siyan Liu, Guannan Zhang, Xiaoping Wang, Zhongcan Xiao, Zachary Morgan, Sylwia Pawledzio, Thomas Proffen, Christina Hoffmann, Huibo Cao, Bryan C Chakoumakos, Yaohua Liu","doi":"10.1063/4.0000279","DOIUrl":"10.1063/4.0000279","url":null,"abstract":"We introduce a computational framework that integrates artificial intelligence (AI), machine learning, and high-performance computing to enable real-time steering of neutron scattering experiments using an edge-to-exascale workflow. Focusing on time-of-flight neutron event data at the Spallation Neutron Source, our approach combines temporal processing of four-dimensional neutron event data with predictive modeling for multidimensional crystallography. At the core of this workflow is the Temporal Fusion Transformer model, which provides voxel-level precision in predicting 3D neutron scattering patterns. The system incorporates edge computing for rapid data preprocessing and exascale computing via the Frontier supercomputer for large-scale AI model training, enabling adaptive, data-driven decisions during experiments. This framework optimizes neutron beam time, improves experimental accuracy, and lays the foundation for automation in neutron scattering. Although real-time experiment steering is still in the proof-of-concept stage, the demonstrated potential of this system offers a substantial reduction in data processing time from hours to minutes via distributed training, and significant improvements in model accuracy, setting the stage for widespread adoption across neutron scattering facilities and more efficient exploration of complex material systems.","PeriodicalId":48683,"journal":{"name":"Structural Dynamics-Us","volume":"11 6","pages":"064303"},"PeriodicalIF":2.3,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11672204/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142904018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comprehensive characterization of gas dynamic virtual nozzles for x-ray free-electron laser experiments. 用于 X 射线自由电子激光实验的气体动态虚拟喷嘴的综合表征。

IF 2.3 2区物理与天体物理

Structural Dynamics-Us Pub Date : 2024-11-26 eCollection Date: 2024-11-01 DOI: 10.1063/4.0000262

Konstantinos Karpos, Sahba Zaare, Dimitra Manatou, Roberto C Alvarez, Vivek Krishnan, Clint Ottmar, Jodi Gilletti, Aian Pableo, Diandra Doppler, Adil Ansari, Reza Nazari, Alexandra Ros, Richard A Kirian

引用次数: 0