Pub Date : 2024-10-02DOI: 10.1038/s42005-024-01810-7
Daria Popova-Gorelova, Robin Santra
Resolving laser-driven electron dynamics on their natural time and length scales is essential for understanding and controlling light-induced phenomena. Capabilities to reveal these dynamics are limited by challenges in interpreting wave mixing of a driving and a probe pulse, low energy resolution at ultrashort time scales and a lack of atomic-scale resolution by standard spectroscopic techniques. Here, we demonstrate how ultrafast x-ray diffraction can access fundamental information on laser-driven electronic motion in solids. We propose a method based on subcycle-resolved x-ray-optical wave mixing that allows for a straightforward reconstruction of key properties of strong-field-induced electron dynamics with atomic spatial resolution. Namely, this technique provides both phases and amplitudes of the spatial Fourier transform of optically-induced charge distributions, their temporal behavior, and the direction of the instantaneous microscopic optically-induced electron current flow. It captures the rich microscopic structures and symmetry features of laser-driven electronic charge and current density distributions. Manipulation of materials properties by laser driving can lead to future technological applications, but a complete picture of its mechanisms is missing. In their paper, authors propose a method based on ultrafast x-ray diffraction that allows for resolving laser-driven electron dynamics on their natural time and length scales.
在自然时间和长度尺度上解析激光驱动的电子动力学对于理解和控制光诱导现象至关重要。由于在解释驱动脉冲和探测脉冲的混合波方面存在挑战、超短时间尺度的能量分辨率低以及标准光谱技术缺乏原子尺度的分辨率，揭示这些动态的能力受到了限制。在这里，我们展示了超快 X 射线衍射如何获取固体中激光驱动电子运动的基本信息。我们提出了一种基于亚周期分辨 X 射线光波混合的方法，可以直接重建强场诱导电子动力学的关键特性，并具有原子空间分辨率。也就是说，这种技术可以提供光诱导电荷分布的空间傅立叶变换的相位和振幅、它们的时间行为以及瞬时微观光诱导电子流的方向。它能捕捉到激光驱动的电子电荷和电流密度分布的丰富微观结构和对称特征。通过激光驱动对材料特性的操纵可带来未来的技术应用，但对其机理的完整描述尚缺。在他们的论文中，作者提出了一种基于超快 X 射线衍射的方法，可以在自然时间和长度尺度上解析激光驱动的电子动力学。
{"title":"Atomic-scale imaging of laser-driven electron dynamics in solids","authors":"Daria Popova-Gorelova, Robin Santra","doi":"10.1038/s42005-024-01810-7","DOIUrl":"10.1038/s42005-024-01810-7","url":null,"abstract":"Resolving laser-driven electron dynamics on their natural time and length scales is essential for understanding and controlling light-induced phenomena. Capabilities to reveal these dynamics are limited by challenges in interpreting wave mixing of a driving and a probe pulse, low energy resolution at ultrashort time scales and a lack of atomic-scale resolution by standard spectroscopic techniques. Here, we demonstrate how ultrafast x-ray diffraction can access fundamental information on laser-driven electronic motion in solids. We propose a method based on subcycle-resolved x-ray-optical wave mixing that allows for a straightforward reconstruction of key properties of strong-field-induced electron dynamics with atomic spatial resolution. Namely, this technique provides both phases and amplitudes of the spatial Fourier transform of optically-induced charge distributions, their temporal behavior, and the direction of the instantaneous microscopic optically-induced electron current flow. It captures the rich microscopic structures and symmetry features of laser-driven electronic charge and current density distributions. Manipulation of materials properties by laser driving can lead to future technological applications, but a complete picture of its mechanisms is missing. In their paper, authors propose a method based on ultrafast x-ray diffraction that allows for resolving laser-driven electron dynamics on their natural time and length scales.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-7"},"PeriodicalIF":5.4,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01810-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-30DOI: 10.1038/s42005-024-01802-7
Anuradha M. Vibhakar, Dmitry D. Khalyavin, Fabio Orlandi, Jamie M. Moya, Shiming Lei, Emilia Morosan, Alessandro Bombardi
Materials exhibiting a spontaneous reversal of spin chirality have the potential to drive the widespread adoption of chiral magnets in spintronic devices. Unlike the majority of chiral magnets that require the application of an external field to reverse the spin chirality, we observe the spin chirality to spontaneously reverse in the topological magnet EuAl4. Using resonant elastic x-ray scattering we demonstrate that all four magnetic phases in EuAl4 are single-k, where the first two magnetic phases are characterized by spin density wave order and the last two by helical spin order. A single spin chirality was stabilised across the 1mm2 sample, and the reversal of spin chirality occurred whilst maintaining a helical magnetic structure. At the onset of the helical magnetism, the crystal symmetry lowers to a chiral monoclinic space group, explaining the asymmetry in the chiral spin order, and establishing a mechanism by which the spin chirality could reverse via magnetostructural coupling. The reversal of spin chirality in the absence of any externally applied field would substantially broaden the use of chiral magnets for applications in spintronic devices. In this manuscript the authors demonstrate the spontaneous reversal of spin chirality in the topological magnet EuAl4 using resonant elastic x-ray scattering.
表现出自旋手性自发反转的材料有望推动手性磁体在自旋电子设备中的广泛应用。大多数手性磁体都需要施加外部磁场才能逆转自旋手性，与之不同的是，我们观察到拓扑磁体 EuAl4 中的自旋手性自发逆转。通过共振弹性 X 射线散射，我们证明了 EuAl4 中的所有四个磁相都是单 K 磁相，其中前两个磁相以自旋密度波序为特征，后两个磁相以螺旋自旋序为特征。在 1 平方毫米的样品中，单一的自旋手性得到了稳定，而自旋手性的逆转是在保持螺旋磁性结构的同时发生的。在螺旋磁性开始时，晶体对称性降低到手性单斜空间群，这解释了手性自旋顺序的不对称性，并建立了通过磁结构耦合实现自旋手性逆转的机制。在没有任何外加磁场的情况下逆转自旋手性将大大拓宽手性磁体在自旋电子器件中的应用。在这篇手稿中，作者利用共振弹性 X 射线散射证明了拓扑磁体 EuAl4 中自旋手性的自发反转。
{"title":"Spontaneous reversal of spin chirality and competing phases in the topological magnet EuAl4","authors":"Anuradha M. Vibhakar, Dmitry D. Khalyavin, Fabio Orlandi, Jamie M. Moya, Shiming Lei, Emilia Morosan, Alessandro Bombardi","doi":"10.1038/s42005-024-01802-7","DOIUrl":"10.1038/s42005-024-01802-7","url":null,"abstract":"Materials exhibiting a spontaneous reversal of spin chirality have the potential to drive the widespread adoption of chiral magnets in spintronic devices. Unlike the majority of chiral magnets that require the application of an external field to reverse the spin chirality, we observe the spin chirality to spontaneously reverse in the topological magnet EuAl4. Using resonant elastic x-ray scattering we demonstrate that all four magnetic phases in EuAl4 are single-k, where the first two magnetic phases are characterized by spin density wave order and the last two by helical spin order. A single spin chirality was stabilised across the 1mm2 sample, and the reversal of spin chirality occurred whilst maintaining a helical magnetic structure. At the onset of the helical magnetism, the crystal symmetry lowers to a chiral monoclinic space group, explaining the asymmetry in the chiral spin order, and establishing a mechanism by which the spin chirality could reverse via magnetostructural coupling. The reversal of spin chirality in the absence of any externally applied field would substantially broaden the use of chiral magnets for applications in spintronic devices. In this manuscript the authors demonstrate the spontaneous reversal of spin chirality in the topological magnet EuAl4 using resonant elastic x-ray scattering.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01802-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Quantum Hall systems are platforms of choice to study topological properties of condensed matter systems and anyonic exchange statistics. In this work we have developed a tunable radiofrequency edge magnetoplasmonic resonator controlled by both the magnetic field and a set of electrostatic gates, meant to serve as a versatile platform for future interferometric devices designed to evidence non-abelian anyons. In our device, gates allow us to change both the size of the resonant cavity and the electronic density of the two-dimensional electron gas. We show that we can continuously control the frequency response of our resonator, making it possible to develop an edge magnetoplasmon interferometer. As we reach smaller sizes of our resonator, finite size effects caused by the measurement probes manifest. In the future, such device will be a valuable tool to investigate the properties of non-abelian anyons in the fractional quantum Hall regime. Edge-magnetoplasmon interferometers have been proposed as a tool to investigate anyonic properties of quasiparticles in the regime of the Fractional Quantum Hall effect. In this work, the authors demonstrate the possibility to control electrostatically the resonance frequency of EMP resonators of micrometric size and explain the role of gates, paving the way toward the realization of anyonic interferometers.
{"title":"Gate tunable edge magnetoplasmon resonators","authors":"Elric Frigerio, Giacomo Rebora, Mélanie Ruelle, Hubert Souquet-Basiège, Yong Jin, Ulf Gennser, Antonella Cavanna, Bernard Plaçais, Emmanuel Baudin, Jean-Marc Berroir, Inès Safi, Pascal Degiovanni, Gwendal Fève, Gerbold C. Ménard","doi":"10.1038/s42005-024-01803-6","DOIUrl":"10.1038/s42005-024-01803-6","url":null,"abstract":"Quantum Hall systems are platforms of choice to study topological properties of condensed matter systems and anyonic exchange statistics. In this work we have developed a tunable radiofrequency edge magnetoplasmonic resonator controlled by both the magnetic field and a set of electrostatic gates, meant to serve as a versatile platform for future interferometric devices designed to evidence non-abelian anyons. In our device, gates allow us to change both the size of the resonant cavity and the electronic density of the two-dimensional electron gas. We show that we can continuously control the frequency response of our resonator, making it possible to develop an edge magnetoplasmon interferometer. As we reach smaller sizes of our resonator, finite size effects caused by the measurement probes manifest. In the future, such device will be a valuable tool to investigate the properties of non-abelian anyons in the fractional quantum Hall regime. Edge-magnetoplasmon interferometers have been proposed as a tool to investigate anyonic properties of quasiparticles in the regime of the Fractional Quantum Hall effect. In this work, the authors demonstrate the possibility to control electrostatically the resonance frequency of EMP resonators of micrometric size and explain the role of gates, paving the way toward the realization of anyonic interferometers.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01803-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-30DOI: 10.1038/s42005-024-01807-2
Pranav Chandarana, Koushik Paul, Mikel Garcia-de-Andoin, Yue Ban, Mikel Sanz, Xi Chen
One of the key applications of near-term quantum computers has been the development of quantum optimization algorithms. However, these algorithms have largely been focused on qubit-based technologies. Here, we propose a hybrid quantum-classical approximate optimization algorithm for photonic quantum computing, specifically tailored for addressing continuous-variable optimization problems. Inspired by counterdiabatic protocols, our algorithm reduces the required quantum operations for optimization compared to adiabatic protocols. This reduction enables us to tackle non-convex continuous optimization within the near-term era of quantum computing. Through illustrative benchmarking, we show that our approach can outperform existing state-of-the-art hybrid adiabatic quantum algorithms in terms of convergence and implementability. Our algorithm offers a practical and accessible experimental realization, bypassing the need for high-order operations and overcoming experimental constraints. We conduct a proof-of-principle demonstration on Xanadu’s eight-mode nanophotonic quantum chip, successfully showcasing the feasibility and potential impact of the algorithm. The authors introduce a hybrid quantum-classical algorithm for photonic quantum computing that focuses on tackling continuous-variable optimization problems using fewer quantum operations than existing methods. The approach shows better performance and practical implementation potential, demonstrated on Xanadu’s quantum chip.
{"title":"Photonic counterdiabatic quantum optimization algorithm","authors":"Pranav Chandarana, Koushik Paul, Mikel Garcia-de-Andoin, Yue Ban, Mikel Sanz, Xi Chen","doi":"10.1038/s42005-024-01807-2","DOIUrl":"10.1038/s42005-024-01807-2","url":null,"abstract":"One of the key applications of near-term quantum computers has been the development of quantum optimization algorithms. However, these algorithms have largely been focused on qubit-based technologies. Here, we propose a hybrid quantum-classical approximate optimization algorithm for photonic quantum computing, specifically tailored for addressing continuous-variable optimization problems. Inspired by counterdiabatic protocols, our algorithm reduces the required quantum operations for optimization compared to adiabatic protocols. This reduction enables us to tackle non-convex continuous optimization within the near-term era of quantum computing. Through illustrative benchmarking, we show that our approach can outperform existing state-of-the-art hybrid adiabatic quantum algorithms in terms of convergence and implementability. Our algorithm offers a practical and accessible experimental realization, bypassing the need for high-order operations and overcoming experimental constraints. We conduct a proof-of-principle demonstration on Xanadu’s eight-mode nanophotonic quantum chip, successfully showcasing the feasibility and potential impact of the algorithm. The authors introduce a hybrid quantum-classical algorithm for photonic quantum computing that focuses on tackling continuous-variable optimization problems using fewer quantum operations than existing methods. The approach shows better performance and practical implementation potential, demonstrated on Xanadu’s quantum chip.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-9"},"PeriodicalIF":5.4,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01807-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142377237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-20DOI: 10.1038/s42005-024-01779-3
Yu-Dai Tsai, Davide Farnocchia, Marco Micheli, Sunny Vagnozzi, Luca Visinelli
It is important to test the possible existence of fifth forces, as ultralight bosons that would mediate these are predicted to exist in several well-motivated extensions of the Standard Model. Recent work indicated asteroids as promising probes, but applications to real data are lacking so far. Here we use the OSIRIS-REx mission and ground-based tracking data for the asteroid Bennu to derive constraints on fifth forces. Our limits are strongest for mediator masses m ~ (10−18-10−17) eV, where we currently achieve the tightest bounds. These can be translated to a wide class of models leading to Yukawa-type fifth forces, and we demonstrate how they apply to U(1)B dark photons and baryon-coupled scalars. Our results demonstrate the potential of asteroid tracking in probing well-motivated extensions of the Standard Model and ultralight bosons near the fuzzy dark matter range. Asteroid tracking has been demonstrated as a promising and prominent probe of fifth forces arising in several well-motivated models beyond the Standard Model of particle physics. The authors use the state-of-art tracking data for the asteroid Bennu from the OSIRIS-REx mission to derive the tightest limits on fifth forces and ultralight dark matter at the lengths of solar-system objects.
对可能存在的第五种力进行测试非常重要，因为在标准模型的几个动机良好的扩展中，预测会存在介导第五种力的超轻玻色子。最近的工作表明小行星是很有希望的探测器，但迄今为止还缺乏对真实数据的应用。在这里，我们利用 OSIRIS-REx 任务和小行星贝努的地面跟踪数据，推导出对第五力的限制。我们对介质质量 m ~ (10-18-10-17) eV 的限制是最强的，目前我们在这方面达到了最严格的界限。这些限制可以转化为导致育川型第五力的多种模型，我们还演示了它们如何适用于 U(1)B 暗光子和重子耦合标量。我们的结果证明了小行星追踪在探测标准模型的动机良好的扩展和模糊暗物质范围附近的超轻玻色子方面的潜力。小行星追踪已被证明是对粒子物理标准模型之外的几个动机良好的模型中产生的第五力的一种有前途的突出探测。作者利用 OSIRIS-REx 任务对小行星贝努（Bennu）的最新跟踪数据，推导出太阳系天体长度上第五力和超轻暗物质的最严格限制。
{"title":"Constraints on fifth forces and ultralight dark matter from OSIRIS-REx target asteroid Bennu","authors":"Yu-Dai Tsai, Davide Farnocchia, Marco Micheli, Sunny Vagnozzi, Luca Visinelli","doi":"10.1038/s42005-024-01779-3","DOIUrl":"10.1038/s42005-024-01779-3","url":null,"abstract":"It is important to test the possible existence of fifth forces, as ultralight bosons that would mediate these are predicted to exist in several well-motivated extensions of the Standard Model. Recent work indicated asteroids as promising probes, but applications to real data are lacking so far. Here we use the OSIRIS-REx mission and ground-based tracking data for the asteroid Bennu to derive constraints on fifth forces. Our limits are strongest for mediator masses m ~ (10−18-10−17) eV, where we currently achieve the tightest bounds. These can be translated to a wide class of models leading to Yukawa-type fifth forces, and we demonstrate how they apply to U(1)B dark photons and baryon-coupled scalars. Our results demonstrate the potential of asteroid tracking in probing well-motivated extensions of the Standard Model and ultralight bosons near the fuzzy dark matter range. Asteroid tracking has been demonstrated as a promising and prominent probe of fifth forces arising in several well-motivated models beyond the Standard Model of particle physics. The authors use the state-of-art tracking data for the asteroid Bennu from the OSIRIS-REx mission to derive the tightest limits on fifth forces and ultralight dark matter at the lengths of solar-system objects.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-7"},"PeriodicalIF":5.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01779-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142275111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-20DOI: 10.1038/s42005-024-01805-4
Dalei Jing, Ruixin Lu, Alexander Farutin, Ziyu Guo, Fan Wang, Wen Wang, Chaouqi Misbah, Yi Sui
The dynamics of soft microparticles enclosed in a droplet flowing in a channel is an unexplored fundamental problem that lies at the heart of numerous applications, including droplet-based microfluidics, tissue engineering and smart material synthesis. Here we show that enclosing a flexible capsule into a droplet can amplify the capsule’s deformation parameters in channel flow by up to two orders of magnitude. Previously unreported capsule equilibrium shapes in channel flow, including an oblate spheroid and a reversed bullet, have also been discovered. We propose two theoretical models to predict the equilibrium position of the capsule inside the droplet, and estimate the capsule deformation, respectively. The present study provides an effective but simple approach to enhance and control the deformation of soft particles in a flowing suspension, which may inspire widespread applications, from high-throughput single-cell mechanical phenotyping, enhanced cross-membrane drug delivery, to manufacturing shape-controlled non-spherical particles and artificial cells. Enhancing deformation of soft microparticles such as cells, capsules and vesicles has widespread applications in cell phenotyping, drug/gene delivery and smart material synthesis. Here, the authors demonstrate that enclosing a capsule into a droplet can amplify the capsule deformation parameter by up to two orders of magnitude, compared with an isolated capsule experiencing identical channel flow conditions.
{"title":"Droplets can enhance microcapsule deformation in channel flow","authors":"Dalei Jing, Ruixin Lu, Alexander Farutin, Ziyu Guo, Fan Wang, Wen Wang, Chaouqi Misbah, Yi Sui","doi":"10.1038/s42005-024-01805-4","DOIUrl":"10.1038/s42005-024-01805-4","url":null,"abstract":"The dynamics of soft microparticles enclosed in a droplet flowing in a channel is an unexplored fundamental problem that lies at the heart of numerous applications, including droplet-based microfluidics, tissue engineering and smart material synthesis. Here we show that enclosing a flexible capsule into a droplet can amplify the capsule’s deformation parameters in channel flow by up to two orders of magnitude. Previously unreported capsule equilibrium shapes in channel flow, including an oblate spheroid and a reversed bullet, have also been discovered. We propose two theoretical models to predict the equilibrium position of the capsule inside the droplet, and estimate the capsule deformation, respectively. The present study provides an effective but simple approach to enhance and control the deformation of soft particles in a flowing suspension, which may inspire widespread applications, from high-throughput single-cell mechanical phenotyping, enhanced cross-membrane drug delivery, to manufacturing shape-controlled non-spherical particles and artificial cells. Enhancing deformation of soft microparticles such as cells, capsules and vesicles has widespread applications in cell phenotyping, drug/gene delivery and smart material synthesis. Here, the authors demonstrate that enclosing a capsule into a droplet can amplify the capsule deformation parameter by up to two orders of magnitude, compared with an isolated capsule experiencing identical channel flow conditions.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-10"},"PeriodicalIF":5.4,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01805-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142275112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-19DOI: 10.1038/s42005-024-01799-z
Jun Sun, Fariba Karimi
Social and technical networks undergo constant evolution driven by both existing entities and newcomers. In academia, research papers are continually cited by new papers, while senior researchers integrate newly arrived junior researchers into their academic networks. Moreover, social systems can be influenced by external factors that could indirectly impact their growth patterns. For instance, systematic discrimination against certain groups in academia or managerial positions can impede their long-term growth, especially when combined with group-level preferences in hiring or adoption, as observed in our study. To address this, we introduce a network growth and adoption model where generalised preferential attachment and asymmetric mixing act as the two fundamental mechanisms of growth and adoption. We show analytically and numerically that these mechanisms can recover the empirical properties of citation and collaboration growth, as well as the inequalities observed in the growth dynamics of groups. This model can be used to investigate the effect of intervention in group mixing preferences to overcome the cumulative disparities in the group-level dynamics. The authors introduce a network growth and adoption model with preferential attachment and asymmetric mixing that can explain the inequalities observed in the group growth dynamics in scientific citation and collaboration. This model can be used to investigate the effect of intervention in group mixing preferences to overcome cumulative disparities.
{"title":"Emergence of group size disparity in growing networks with adoption","authors":"Jun Sun, Fariba Karimi","doi":"10.1038/s42005-024-01799-z","DOIUrl":"10.1038/s42005-024-01799-z","url":null,"abstract":"Social and technical networks undergo constant evolution driven by both existing entities and newcomers. In academia, research papers are continually cited by new papers, while senior researchers integrate newly arrived junior researchers into their academic networks. Moreover, social systems can be influenced by external factors that could indirectly impact their growth patterns. For instance, systematic discrimination against certain groups in academia or managerial positions can impede their long-term growth, especially when combined with group-level preferences in hiring or adoption, as observed in our study. To address this, we introduce a network growth and adoption model where generalised preferential attachment and asymmetric mixing act as the two fundamental mechanisms of growth and adoption. We show analytically and numerically that these mechanisms can recover the empirical properties of citation and collaboration growth, as well as the inequalities observed in the growth dynamics of groups. This model can be used to investigate the effect of intervention in group mixing preferences to overcome the cumulative disparities in the group-level dynamics. The authors introduce a network growth and adoption model with preferential attachment and asymmetric mixing that can explain the inequalities observed in the group growth dynamics in scientific citation and collaboration. This model can be used to investigate the effect of intervention in group mixing preferences to overcome cumulative disparities.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01799-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-19DOI: 10.1038/s42005-024-01801-8
L. M. Martelo, Aires Ferreira
The emergence of strong relativistic spin-orbit effects in low-dimensional systems provides a rich opportunity for exploring unconventional states of matter. Here, we present a route to realise tunable relativistic band structures based on the lateral patterning of proximity-induced spin-orbit coupling. The concept is illustrated on a patterned graphene–transition metal dichalcogenide heterostructure, where the spatially periodic spin-orbit coupling induces a rich mini-band structure featuring massless and massive Dirac bands carrying large spin Berry curvature. The envisaged systems support robust and gate-tunable spin Hall responses driven by the quantum geometry of mini-bands, which can be tailored through metasurface fabrication methods and twisting effects. These findings open pathways to two-dimensional quantum material design and low-power spintronic applications. Engineering sizeable spin-orbit coupling (SOC) in graphene generates effects unmatched in traditional low-dimensional systems. Here, the authors show that the periodic modulation of SOC in 1D patterned graphene heterostructures leads to unusual mini-band structures with symmetry-protected Dirac cones featuring enhanced spin Berry curvature, which paves the way to tunable spin Hall responses.
{"title":"Designer spin-orbit superlattices: symmetry-protected Dirac cones and spin Berry curvature in two-dimensional van der Waals metamaterials","authors":"L. M. Martelo, Aires Ferreira","doi":"10.1038/s42005-024-01801-8","DOIUrl":"10.1038/s42005-024-01801-8","url":null,"abstract":"The emergence of strong relativistic spin-orbit effects in low-dimensional systems provides a rich opportunity for exploring unconventional states of matter. Here, we present a route to realise tunable relativistic band structures based on the lateral patterning of proximity-induced spin-orbit coupling. The concept is illustrated on a patterned graphene–transition metal dichalcogenide heterostructure, where the spatially periodic spin-orbit coupling induces a rich mini-band structure featuring massless and massive Dirac bands carrying large spin Berry curvature. The envisaged systems support robust and gate-tunable spin Hall responses driven by the quantum geometry of mini-bands, which can be tailored through metasurface fabrication methods and twisting effects. These findings open pathways to two-dimensional quantum material design and low-power spintronic applications. Engineering sizeable spin-orbit coupling (SOC) in graphene generates effects unmatched in traditional low-dimensional systems. Here, the authors show that the periodic modulation of SOC in 1D patterned graphene heterostructures leads to unusual mini-band structures with symmetry-protected Dirac cones featuring enhanced spin Berry curvature, which paves the way to tunable spin Hall responses.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-7"},"PeriodicalIF":5.4,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01801-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2024-09-18DOI: 10.1038/s42005-024-01796-2
Zirui Xiao, Jian Li, Kaiping Xue, Nenghai Yu, Ruidong Li, Qibin Sun, Jun Lu
Quantum networks can establish End-to-End (E2E) entanglement connections between two arbitrary nodes with desired entanglement fidelity by performing entanglement purification to support quantum applications reliably. The existing works mainly focus on link-level purification scheduling and lack consideration of purifications at network-level, which fails to offer an effective solution for concurrent requests, resulting in low throughput. However, efficiently allocating scarce resources to purify entanglement for concurrent requests remains a critical but unsolved problem. To address this problem, we explore the purification resource scheduling problem from a network-level perspective. We analyze the cost of purification, design the E2E fidelity calculation method in detail, and propose an approach called Purification Scheduling Control (PSC). The basic idea of PSC is to determine the appropriate purification through jointly optimizing purification and resource allocation processes based on conflict avoidance. We conduct extensive experiments that show that PSC can maximize throughput under the fidelity requirement. In quantum networks, entanglement purification is required to ensure that the E2E fidelity of the entanglement connections can support quantum applications reliably. Here, the authors explore the purification resource scheduling problem from a network-level perspective by jointly optimizing purification and resource allocation processes to maximize the throughput under the fidelity requirement.
{"title":"Purification scheduling control for throughput maximization in quantum networks","authors":"Zirui Xiao, Jian Li, Kaiping Xue, Nenghai Yu, Ruidong Li, Qibin Sun, Jun Lu","doi":"10.1038/s42005-024-01796-2","DOIUrl":"10.1038/s42005-024-01796-2","url":null,"abstract":"Quantum networks can establish End-to-End (E2E) entanglement connections between two arbitrary nodes with desired entanglement fidelity by performing entanglement purification to support quantum applications reliably. The existing works mainly focus on link-level purification scheduling and lack consideration of purifications at network-level, which fails to offer an effective solution for concurrent requests, resulting in low throughput. However, efficiently allocating scarce resources to purify entanglement for concurrent requests remains a critical but unsolved problem. To address this problem, we explore the purification resource scheduling problem from a network-level perspective. We analyze the cost of purification, design the E2E fidelity calculation method in detail, and propose an approach called Purification Scheduling Control (PSC). The basic idea of PSC is to determine the appropriate purification through jointly optimizing purification and resource allocation processes based on conflict avoidance. We conduct extensive experiments that show that PSC can maximize throughput under the fidelity requirement. In quantum networks, entanglement purification is required to ensure that the E2E fidelity of the entanglement connections can support quantum applications reliably. Here, the authors explore the purification resource scheduling problem from a network-level perspective by jointly optimizing purification and resource allocation processes to maximize the throughput under the fidelity requirement.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01796-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142251899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
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