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arXiv 2025年

作者： Cholsuk, Chanaprom Çakan, Aslı Deckert, Volker Suwanna, Sujin Vogl, Tobias Department of Computer Engineering TUM School of Computation Information and Technology Technical University of Munich Munich80333 Germany Munich80799 Germany Institute of Physical Chemistry Friedrich-Schiller University Jena07743 Germany Leibniz Institute of Photonic Technology Jena07745 Germany Abbe Center of Photonics Institute of Applied Physics Friedrich Schiller University Jena Jena07745 Germany Optical and Quantum Physics Laboratory Department of Physics Faculty of Science Mahidol University Bangkok10400 Thailand

Point defects in solid-state quantum systems are vital for enabling single-photon emission at specific wavelengths, making their precise identification essential for advancing applications in quantum technologies. However, pinpointing the microscopic origins of these defects remains a challenge. In this work, we propose Raman spectroscopy as a robust strategy for defect identification. Using density functional theory, we systematically characterize the Raman signatures of 100 defects in hexagonal boron nitride (hBN) spanning periodic groups III to VI, encompassing around 30,000 phonon modes. Our findings reveal that the local atomic environment plays a pivotal role in shaping the Raman lineshape, enabling the narrowing of potential defect candidates. Furthermore, we demonstrate that Raman spectroscopy can differentiate defects based on their spin and charge states as well as strain-induced variations, implying the versatility of this approach. Therefore, this study not only provides a comprehensive theoretical database of Raman spectra for hBN defects but also establishes a novel experiment framework for using tip-enhanced Raman spectroscopy to identify point defects. More broadly, our approach offers a universal method for defect identification in any quantum materials. Copyright © 2025, The Authors. All rights reserved.

关键词： Point defects

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A Proof of the Weak Gravity Conjecture via Leading-Order Quantum Gravity Effects

arXiv

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arXiv 2025年

作者： Xiao, Yong Wang, Qiang Zhang, Aonan Key Laboratory of High-precision Computation Application of Quantum Field Theory of Hebei Province College of Physical Science and Technology Hebei University Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding071002 China Higgs Centre for Theoretical Physics School of Mathematics University of Edinburgh EdinburghEH9 3FD United Kingdom

The weak gravity conjecture posits that there should exist at least one state with a charge-to-mass ratio q/M > 1, ensuring that an extremal charged black hole can still decay. In this paper, we study the corrections to the thermodynamics of Reissner-Nordström black holes within an effective field theory framework. The effective action originates from integrating out massless particles, including gravitons, at one-loop level. As a proof of the weak gravity conjecture, we show that these quantum gravity effects naturally lead to the super-extremality of charged black holes. It is important to note that our results are model-independent and have predictive capacities. Copyright © 2025, The Authors. All rights reserved.

关键词： Black holes

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Dynamical instability of the dark state in the conversion of Bose-Fermi mixtures into stable molecules

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Chinese physics B 2011年第8期20卷 71-76页

作者：孟少英吴炜陈希浩张静傅立斌 Department of Physics Liaoning University Science and Technology Computation Physics Laboratory Institute of Applied Physics and Computational Mathematics Centre for Applied Physics and Technology Peking University

In this paper, we investigate the dynamical instability of the dark state in the conversion of Bose-Fermi mixtures into stable molecules through a stimulated Raman adiabatic passage aided by Feshbach resonance. We analytically obtain the regions where the dynamical instability appears and find that such instability in the Bose-Fermi mixture system is caused not only by bosonic interparticle interactions but also by Pauli blocking terms, which is different from the scenario of a pure bosonic system where instability is induced by nonlinear interparticle collisions. Taking a 40K-87Rb mixture as an example, we give the unstable regions numerically.

关键词： Bose-Fermi mixture dynamical instability dark state

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Photo-luminescence properties of ion implanted Er3+-defects in 4H-SiCOI towards integrated quantum photonics

arXiv

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arXiv 2025年

作者： Bader, Joshua Lim, Shao Qi Inam, Faraz Ahmed Johnson, Brett C. Peruzzo, Alberto McCallum, Jeffrey Li, Qing Castelletto, Stefania School of Engineering RMIT University MelbourneVIC3000 Australia Quantum Photonics Laboratory Centre for Quantum Computation and Communication Technology School of Engineering RMIT University MelbourneVIC3000 Australia Centre for Quantum Computation and Communication Technology School of Physics The University of Melbourne MelbourneVIC3010 Australia Department of Physics Aligarh Muslim University Aligarh202002 India School of Science RMIT University Melbourne3001 Australia Advanced Research Department Qubit Pharmaceuticals Paris75014 France Electrical and Computer Engineering Carnegie Mellon University PittsburghPA15213 United States

Colour centres hosted in solid-state materials such as silicon carbide and diamond are promising candidates for integration into chip-scale quantum systems. Specifically, the incorporation of these colour centres within photonic integrated circuits may enable precise control over their inherent photo-physical properties through strong light-matter interaction. Here, we investigate ion-implanted erbium (Er3+) defects embedded in thin-film 4H-silicon-carbide-on-insulator (4H-SiCOI). Optimized implantation conditions and thermal annealing processes designed to enhance the emission characteristics of the Er3+-defect are reported. By examining key properties such as photoluminescence intensity, optical lifetime, and polarization, we present an analysis of ensemble Er3+-defects within 4H-SiCOI, providing insights into their potential for future quantum applications. © 2025, CC0.

关键词： Nanocrystals

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CrossConvPyramid: Deep Multimodal Fusion for Epileptic Magnetoencephalography Spike Detection

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IEEE Journal of Biomedical and Health Informatics 2025年第5期29卷 3194-3205页

作者： Liang Zhang Shurong Sheng Xiongfei Wang Jia-Hong Gao Yi Sun Kuntao Xiao Wanli Yang Pengfei Teng Guoming Luan Zhao Lv AHU-IAI AI Joint Laboratory School of Artificial Intelligence Anhui University Hefei China Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing Institute of Artificial Intelligence Hefei Comprehensive National Science Center Hefei China Department of Neurosurgery Beijing Key Laboratory of Epilepsy Sanbo Brain Hospital Capital Medical University Beijing China McGovern Institute for Brain Research Peking University Beijing China Center for MRI Research Academy for Advanced Interdisciplinary Studies Peking University Beijing China Beijing City Key Lab for Medical Physics and Engineering Institute of Heavy Ion Physics School of Physics Peking University Beijing China Institute of Artificial Intelligence Hefei Comprehensive National Science Center Hefei China Anhui Province Key Laboratory of Multimodal Cognitive Computation School of Computer Science and Technology Anhui University Hefei China

Magnetoencephalography (MEG) is a vital non-invasive tool for epilepsy analysis, as it captures high-resolution signals that reflect changes in brain activity over time. The automated detection of epileptic spikes within these signals can significantly reduce the labor and time required for manual annotation of MEG recording data, thereby aiding clinicians in identifying epileptogenic foci and evaluating treatment prognosis. Research in this domain often utilizes the raw, multi-channel signals from MEG scans for spike detection, commonly neglecting the multi-channel spiking patterns from spatially adjacent channels. Moreover, epileptic spikes share considerable morphological similarities with artifact signals within the recordings, posing a challenge for models to differentiate between the two. In this paper, we introduce a multimodal fusion framework that addresses these two challenges collectively. Instead of relying solely on the signal recordings, our framework also mines knowledge from their corresponding topography-map images, which encapsulate the spatial context and amplitude distribution of the input signals. To facilitate more effective data fusion, we present a novel multimodal feature fusion technique called CrossConvPyramid, built upon a convolutional pyramid architecture augmented by an attention mechanism. It initially employs cross-attention and a convolutional pyramid to encode inter-modal correlations within the intermediate features extracted by individual unimodal networks. Subsequently, it utilizes a self-attention mechanism to refine and select the most salient features from both inter-modal and unimodal features, specifically tailored for the spike classification task. Our method achieved the average F1 scores of 92.88% and 95.23% across two distinct real-world MEG datasets from separate centers, respectively outperforming the current state-of-the-art by 2.31% and 0.88%. We plan to release the code on GitHub later.

关键词： Feature extraction Recording Brain modeling Attention mechanisms Convolution Bioinformatics Epilepsy Electroencephalography computational modeling physics

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Instability, adiabaticity, and controlling effects of external fields for the dark state in a homonuclear atom tetramer conversion system

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Chinese physics B 2014年第4期23卷 125-129页

作者：孟少英陈希浩吴炜傅立斌 Department of Physics Liaoning University Science and Technology Computation Physics Laboratory Institute of Applied Physics and Computational Mathematics Center for Applied Physics and Technology Peking University

In the present paper, we investigate the instability, adiabaticity, and controlling effects of external fields for a dark state in a homonuclear atom-tetramer conversion that is implemented by a generalized stimulated Raman adiabatic passage. We analytically obtain the regions for the appearance of dynamical instability and study the adiabatic evolution by a newly defined adiabatic fidelity. Moreover, the effects of the external field parameters and the spontaneous emissions on the conversion efficiency are also investigated.

关键词： dynamical instability adiabatic fidelity dark state atom-molecule conversion

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Direct Expression for One-Loop Tensor Reduction with Lorentz Indices via Generating Function

arXiv

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arXiv 2025年

作者： Hu, Chang Hu, Yifan Shen, Jiyuan College of Physics Science and Technology Hebei University Baoding071002 China Hebei Key Laboratory of High-precision Computation and Application of Quantum Field Theory Baoding071002 China Hebei Research Center of the Basic Discipline for Computational Physics Baoding071002 China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study UCAS Hangzhou310024 China University of Chinese Academy of Sciences Beijing100049 China Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China

In [1], we derived a direct expression for one-loop tensor reduction using generating functions and Feynman parametrization in projective space, avoiding recursive relations. However, for practical applications, this expression still presents two challenges: (1) While the final reduction coefficients are expressed in terms of the dimension D and Mandelstam variables, the given expression explicitly contains irrational functions;(2) The expression involves an auxiliary vector R, which can be eliminated via differentiation ∂/∂R , but the presence of irrational terms making differentiation cumbersome. (3) Most practical applications require the tensor form with Lorentz indices. In this paper, we provide a rational form of the reduction coefficients with Lorentz indices, free from recursion. Additionally, We provide a pure Wolfram Mathematica implementation of the code. Our practical tests demonstrate that this direct expression achieves significantly higher computational efficiency compared to the traditional Passarino-Veltman (PV) reduction or other recursion-based methods. © 2025, CC0.

关键词： Tensors

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Fourth-Order Interference in Femtosecond Spontaneous Parametric Down-Conversion

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Chinese physics Letters 2000年第10期17卷 726-727页

作者： JIANG Yun-Kun SHI Bao-Sen LI Jian FAN xiao-feng GUO Guang-Can Laboratory of Quantum Communication and Quantum Computation Department of PhysicsUniversity of Science and Technology of ChinaHefei 230026

We report a fourth-order interference experiment in which pairs of photons are produced in spontaneous parametric down-conversion pumped by femtosecond pulses interfere in a Hong-Ou-Mandel *** visibilityof the interfe... 详细信息

关键词： theory. exceeding parametric

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A Two-Party Probabilistic Communication Complexity Scenario via Werner States

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Chinese physics Letters 2001年第10期18卷 1301-1303页

作者： XUE Peng LI Chuan-Feng GUO Guang-Can Laboratory of Quantum Coniniunication and Quantum Computation and Department of Physics University of Science and Technology of ChinaHefei 230026

We propose a probabilistic two-party communication complexity scenario with a prior Werner state and analyse the communication abilities of quantum correlations (entanglements) and classical correlations. This process... 详细信息

关键词： states. monotone Complexity

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Telebroadcasting of a Cat-like State via Local Operations

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Chinese physics Letters 2001年第9期18卷 1159-1162页

作者： WEN Hai-Dan LI Chuan-Feng GUO Guang-Can Laboratory of Quantum Communication and Quantum Computation and Department of Physics University of Science and Technology ofChinaHefei 230026

The quantum telebroadcasting of a cat-like state in combination with the quantum teleportation and the local copying of entanglement is presented. This gives a general way of distributing entanglement among distant pa... 详细信息

关键词： quantum technology. local

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