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Electron Acceleration in Carbon Nanotubes

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arXiv 2025年

作者： Bonţoiu, Cristian Bonatto, Alexandre Apsimon, Öznur Bandiera, Laura Cavoto, Gianluca Drebot, Illya Gatti, Giancarlo Giner-Navarro, Jorge Lei, Bifeng Martín-Luna, Pablo Rago, Ilaria Pérez, Juan Rodríguez Nunes, Bruno Silveira Sytov, Alexei Valagiannopoulos, Costas Welsch, Carsten P. Xia, Guoxing Resta-López, Javier Department of Physics University of Liverpool Oxford Street LiverpoolL69 7ZE United Kingdom Graduate Program in Information Technology and Healthcare Management the Beam Physics Group Federal University of Health Sciences of Porto Alegre RS Porto Alegre90050-170 Brazil Department of Physics and Astronomy University of Manchester Oxford Road ManchesterM13 9PL United Kingdom Cockroft Institute Keckwick Lane Daresbury WarringtonWA4 4AD United Kingdom INFN Sezione di Ferrara Via Saragat 1 Ferrara44122 Italy Dipartimento di Fisica Sapienza Università di Roma Piazzale Aldo Moro 2 Roma00185 Italy INFN Sezione di Roma Piazzale Aldo Moro 2 Rome00185 Italy INFN Sezione di Milano Via G. Celoria 16 Milano20133 Italy Centro de Láseres Pulsados Building M5 Science Park Calle Adaja 8 Salamanca Villamayor37185 Spain Universidad de Valencia Paterna46071 Spain Universidad de Valencia CSIC Paterna46980 Spain Nuclear and Energy Research Institute IPEN–CNEN SP São Paulo Brazil National Technical University of Athens School of Electrical and Computer Engineering Zografou157 73 Greece Departamento de Física Aplicada y Electromagnetismo Universidad de Valencia Burjassot46100 Spain

Laser wakefield acceleration (LWFA) may achieve TeV/m gradients using high-density solid-state plasmas as accelerating media. However, the application of bulk solid materials requires attosecond laser pulses, such as X-ray lasers, to drive wakefields at these high densities. Additionally, the short wakefield wavelengths associated with solid-state plasmas greatly limit the accelerating length. An alternative approach employs 2D carbon-based nanomaterials, like graphene or carbon nanotubes (CNTs), configured into structured targets. These nanostructures are designed with voids or low-density regions to effectively reduce the overall plasma density. This reduction enables the use of longer-wavelength lasers and also extends the plasma wavelength and the acceleration length. In this study, we present, to our knowledge, the first numerical demonstration of electron acceleration via self-injection into a wakefield bubble driven by an infrared laser pulse in structured CNT targets, similar to the behavior observed in gaseous plasmas for LWFA in the nonlinear (or bubble) regime. Using the PIConGPU code, bundles of CNTs are modeled in a 3D geometry as 25 nm-thick carbon tubes with an initial density of 1022 cm−3. The carbon plasma is ionized by a three-cycle, 800 nm wavelength laser pulse with a peak intensity of 1021 W cm−2, achieving an effective plasma density of 1020 cm−3. The same laser also drives the wakefield bubble, responsible for the electron self-injection and acceleration. Simulation results indicate that fs-long electron bunches with hundreds of pC charge can be self-injected and accelerated at gradients exceeding 1 TeV/m. Both charge and accelerating gradient figures are unprecedented when compared with LWFA in gaseous plasma. © 2025, CC BY-NC-ND.

关键词： X ray lasers

Sustainable Fuel Production: Sustainable Fuel Production from Ambient Moisture via Ferroelectrically Driven MoS2Nanosheets (Adv. Mater. 25/2020)

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Advanced materials 2020年第25期32卷

作者： Lin Yang Leyi Loh Dilip Krishna Nandakumar Wanheng Lu Mengqi Gao Xue Le Charlotte Wee Kaiyang Zeng Michel Bosman Swee Ching Tan Department of Materials Science and Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117575 Singapore Department of Electrical and Computer Engineering National University of Singapore 4 Engineering Drive 3 Singapore 117583 Singapore Department of Mechanical Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117576 Singapore

Ferroelectric Switching: Giant Ferroelectric Resistance Switching Controlled by a Modulatory Terminal for Low-Power Neuromorphic In-Memory Computing (Adv. Mater. 21/2021)

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Advanced materials 2021年第21期33卷

作者： Fei Xue Xin He Zhenyu Wang José Ramón Durán Retamal Zheng Chai Lingling Jing Chenhui Zhang Hui Fang Yang Chai Tao Jiang Weidong Zhang Husam N. Alshareef Zhigang Ji Lain-Jong Li Jr-Hau He Xixiang Zhang Physical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal 23955-6900 Saudi Arabia National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong University Shanghai 200240 China Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal 23955-6900 Saudi Arabia Department of Electronics and Electrical Engineering Liverpool John Moores University Liverpool L3 3AF UK Computer Science Department Loughborough University Loughborough LE11 3TU UK Department of Applied Physics The Hong Kong Polytechnic University Kowloon Hong Kong China CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and Sensor Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 China Department of Materials Science and Engineering University of New South Wales Kensington NSW 2052 Australia Department of Materials Science and Engineering City University of Hong Kong Kowloon Hong Kong China

Spin-Induced Linear Polarization of Excitonic Emission in Antiferromagnetic van der Waals Crystals

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arXiv 2020年

作者： Wang, Xingzhi Cao, Jun Lu, Zhengguang Cohen, Arielle Kitadai, Hikari Li, Tianshu Wilson, Matthew Lui, Chun Hung Smirnov, Dmitry Sharifzadeh, Sahar Ling, Xi Department of Chemistry Boston University BostonMA02215 United States National High Magnetic Field Laboratory TallahasseeFL32310 United States Department of Physics Florida State University TallahasseeFL32306 United States Division of Materials Science and Engineering Boston University BostonMA02215 United States Department of Physics and Astronomy University of California RiversideCA92521 United States Department of Electrical and Computer Engineering Boston University BostonMA02215 United States Department of Physics Boston University BostonMA02215 United States Photonics Center Boston University BostonMA02215 United States

Antiferromagnets display enormous potential in spintronics owing to its intrinsic nature, including terahertz resonance1,2, multilevel states3,4, and absence of stray fields5,6. Combining with the layered nature, van der Waals (vdW) antiferromagnets hold the promise in providing new insights and new designs in two-dimensional (2D) spintronics. The zero net magnetic moments of vdW antiferromagnets strengthens the spin stability, however, impedes the correlation between spin and other excitation elements, like excitons7,8. Such coupling is urgently anticipated for fundamental magneto-optical studies and potential opto-spintronic devices. Here, we report an ultra-sharp excitonic emission with excellent monochromaticity in antiferromagnetic nickel phosphorus trisulfides (NiPS3) from bulk to atomically thin flakes. We prove that the linear polarization of the excitonic luminescence is perpendicular to the ordered spin orientation in NiPS3. By applying an in-plane magnetic field to alter the spin orientation, we further manipulate the excitonic emission polarization. Such strong correlation between exciton and spins provides new insights for the study of magneto-optics in 2D materials, and hence opens a path for developing opto-spintronic devices and antiferromagnet-based quantum information technologies. Copyright © 2020, The Authors. All rights reserved.

关键词： Van der Waals forces

A Clinician-Friendly Platform for Ophthalmic Image Analysis Without Technical Barriers

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arXiv 2025年

作者： Wang, Meng Lin, Tian Hou, Qingshan Lin, Aidi Wang, Jingcheng Peng, Qingsheng Nguyen, Truong X. Fang, Danqi Zou, Ke Xu, Ting Xue, Cancan Quek, Ten Cheer Yu, Qinkai Liu, Minxin Zhou, Hui Xiao, Zixuan He, Guiqin Liang, Huiyu Shi, Tingkun Chen, Man Liu, Linna Peng, Yuanyuan Wang, Lianyu Hu, Qiuming Chen, Junhong Zhang, Zhenhua Chen, Cheng Zhao, Yitian Liu, Dianbo Wu, Jianhua Chen, Xinjian Zhang, Changqing Nguyen, Triet Thanh Meng, Yanda Zheng, Yalin Tham, Yih Chung Cheung, Carol Y. Fu, Huazhu Chen, Haoyu Cheng, Ching-Yu Centre for Innovation and Precision Eye Health Yong Loo Lin School of Medicine National University of Singapore Singapore119228 Singapore Department of Ophthalmology Yong Loo Lin School of Medicine National University of Singapore Singapore119228 Singapore Joint Shantou International Eye Center Shantou University The Chinese University of Hong Kong Guangdong Shantou515041 China Shantou University Medical College Guangdong Shantou515041 China School of Computer Science and Engineering Northeastern University Liaoning Shenyang110819 China Big Vision Medical Technology Ltd. Suzhou215011 China Singapore Eye Research Institute Singapore National Eye Centre Singapore169856 Singapore Department of Ophthalmology and Visual Sciences The Chinese University of Hong Kong 999077 Hong Kong Binh Dinh Eye Hospital Viet Nam Department of Computer Science University of Exeter ExeterEX4 4RN United Kingdom University of Science and Technology Hospital Guangdong Shenzhen518000 China Shenzhen Qianhai Shekou Free Trade Zone Hospital Guangdong Shenzhen518000 China Department of Ophthalmology Meizhou People’s Hospital Meizhou Academy of Medical Sciences Guangdong Meizhou514000 China Department of Ophthalmology Yeungnam University College of Medicine Daegu42417 Korea Republic of Aier Eye Hospital of Wuhan University Hubei Wuhan430000 China School of Biomedical Engineering Anhui Medical University Anhui Hefei230032 China College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics Jiangsu Nanjing211100 China Guangxi Jingliang Eye Hospital Guangxi Nanning530021 China Puning People’s Hospital Guangdong Jieyang522000 China Shandong Qingdao266042 China Department of Electrical and Electronic Engineering the University of Hong Kong Hong Kong Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Zhejiang Ningbo315201 China School of Electronics and Information Engineering Soochow University

Artificial intelligence (AI) shows remarkable potential in medical imaging diagnostics, but current models typically require retraining when deployed across different clinical centers, limiting their widespread adoption. We introduce GlobeReady, a clinician-friendly AI platform that enables ocular disease diagnosis without retraining/fine-tuning or technical expertise. GlobeReady achieves high accuracy across imaging modalities: 93.9–98.5% for an 11-category fundus photo dataset and 87.2–92.7% for a 15-category OCT dataset. Through training-free local feature augmentation, it addresses domain shifts across centers and populations, reaching an average accuracy of 88.9% across five centers in China, 86.3% in Vietnam, and 90.2% in the UK. The built-in confidence-quantifiable diagnostic approach further boosted accuracy to 94.9–99.4% (fundus) and 88.2–96.2% (OCT), while identifying out-of-distribution cases at 86.3% (49 CFP categories) and 90.6% (13 OCT categories). Clinicians from multiple countries rated GlobeReady highly (average 4.6 out of 5) for its usability and clinical relevance. These results demonstrate GlobeReady’s robust, scalable diagnostic capability and potential to support ophthalmic care without technical barriers. © 2025, CC0.

关键词： Ophthalmology

Erratum: “Two-dimensional porous graphitic carbon nitride C6N7 monolayer: First-principles calculations” [Appl. Phys. Lett. 119, 142102 (2021)]

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Applied Physics Letters 2022年第18期120卷

作者： A. Bafekry M. Faraji M. M. Fadlallah I. Abdolhosseini Sarsari H. R. Jappor S. Fazeli M. Ghergherehchi 1Department of Radiation Application Shahid Beheshti University Tehran Iran 2Micro and Nanotechnology Graduate Program TOBB University of Economics and Technology Sogutozu Caddesi No 43 Sogutozu 06560 Ankara Turkey 3Department of Physics Faculty of Science Benha University 13518 Benha Egypt 4Department of Physics Isfahan University of Technology Isfahan 84156-83111 Iran 5Department of Physics College of Education for Pure Sciences University of Babylon Hilla Iraq 6Department of Material Science and Engineering Sharif University of Technology PO Box 11155-9466 Tehran Iran 7Department of Electrical and Computer Engineering Sungkyunkwan University 16419 Suwon South Korea

The original article1 contains misprints in the values of the elastic parameters. The values of C11 = 258.6 GPa, C22 = 290.8 GPa, and C12 = 70.73 GPa and C13 =

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Nanoscale Strain engineering: Self-Erasable and Rewritable Optoexcitonic Platform for Antitamper Hardware (Advanced Optical materials 21/2020)

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Advanced Optical materials 2020年第21期8卷

作者： Che-Hsuan Cheng Da Seul Yang Jinsang Kim Parag B. Deotare Department of Materials Science and Engineering University of Michigan Ann Arbor MI 48105 USA Macromolecular Science and Engineering University of Michigan Ann Arbor MI 48105 USA Department of Chemical Engineering University of Michigan Ann Arbor MI 48105 USA Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI 48105 USA

Inverse Design of Nanoparticles for Enhanced Raman Scattering

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arXiv 2019年

作者： Christiansen, Rasmus E. Michon, Jérôme Benzaouia, Mohammed Sigmund, Ole Johnson, Steven G. Department of Mechanical Engineering Technical University of Denmark Nils Koppels Allé Building 404 Kongens Lyngby2800 Denmark Department of Mathematics Massachusetts Institute of Technology CambridgeMA02139 United States Department of Materials Science and Engineering Massachusetts Institute of Technology CambridgeMA02139 United States Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States

We show that topology optimization (TO) of metallic resonators can lead to ∼ 102× improvement in surface-enhanced Raman scattering (SERS) efficiency compared to traditional resonant structures such as bowtie antennas. TO inverse design leads to surprising structures very different from conventional designs, which simultaneously optimize focusing of the incident wave and emission from the Raman dipole. We consider isolated metallic particles as well as more complicated configurations such as periodic surfaces or resonators coupled to dielectric waveguides, and the benefits of TO are even greater in the latter case. Our results are motivated by recent rigorous upper bounds to Raman scattering enhancement, and shed light on the extent to which these bounds are achievable. Copyright © 2019, The Authors. All rights reserved.

关键词： Resonators

100pT/cm sensitive MEMS resonant magnetometer from a commercial accelerometer

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arXiv 2019年

作者： Javor, Josh Stange, Alexander Pollock, Corey Fuhr, Nicholas Bishop, David J. Department of Mechanical Engineering Boston University BostonMA02215 United States Division of Materials Science and Engineering Boston University BostonMA02215 United States Department of Electrical and Computer Engineering Boston University BostonMA02215 United States Department of Physics Boston University BostonMA02215 United States Department of Biomedical Engineering Boston University BostonMA02215 United States

Magnetic sensing is present in our everyday interactions with consumer electronics, and also demonstrates potential for measurement of extremely weak biomagnetic fields, such as those of the heart and brain. In this work, we leverage the many benefits of the micro-electromechanical systems (MEMS) devices to fabricate a small, low power, inexpensive sensor whose resolution is in the range of weak biomagnetic fields. The sensor works at room temperature, and is suitable for consumer electronics integration. At present, such biomagnetic fields can only be measured by expensive mechanisms such as optical pumping and superconducting quantum interference devices (SQUIDs). Thus, our sensor suggests the opening of a large phase space for medical and consumer applications. The prototype fabrication is achieved by assembling micro-objects, including a permanent micromagnet, onto a post-release commercial MEMS accelerometer. With this system, we demonstrate a room temperature MEMS magnetometer, whose design is only sensitive to gradient magnetic fields and is generally insensitive to the Earth’s uniform field. In air, the sensor’s response is linear with a resolution of 1.1 nT cm-1 and spans over 3 decades of dynamic range to 4.6 µT cm-1. In 1 mTorr vacuum with 20 dB magnetic shielding, the sensor achieved 100 pT cm-1 resolution at resonance. The theoretical floor of this design is 110 fT cm-1 Hz-1/2 with a resolution of 13 fT cm-1, thus these devices hold promise for both magnetocardiography (MCG) and magnetoencephalography (MEG) applications. Copyright © 2019, The Authors. All rights reserved.

关键词： Magnetometers