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Temperature dependent scaling laws of Rydberg excitons in Cu2O

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Temperature dependent scaling laws of Rydberg excitons in Cu...

Conference on Lasers and Electro-Optics (CLEO)

作者： Aaron Gross HeeBong Yang Dongyeon D. Kang Yusuke Morita Kyung-Soo Choi Kosuke Yoshioka Na Young Kim Institute for Quantum Computing University of Waterloo Waterloo Canada University of Waterloo Waterloo Canada Graduate School of Science the University of Tokyo Tokyo Japan Photon Science Center School of Engineering the University of Tokyo Tokyo Japan

We measure the yellow P-exciton absorption spectra of Cu2O via temperature-dependent spectroscopy (4-100 K). We study exciton resonance spectral properties in terms of peak energy, spectral linewidth, and oscillator s... 详细信息

ISBN: (纸本)9781943580910

关键词： Temperature measurement Temperature dependence Spectroscopy Temperature Excitons Measurement by laser beam Energy measurement

Non-Hermitian Pseudomodes for Strongly Coupled Open Quantum Systems: Unravelings, Correlations and Thermodynamics

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arXiv 2024年

作者： Menczel, Paul Funo, Ken Cirio, Mauro Lambert, Neill Nori, Franco Theoretical Physics Laboratory Cluster for Pioneering Research RIKEN Wakoshi Saitama351-0198 Japan Institute for Molecular Science National Institutes of Natural Sciences Okazaki444-8585 Japan Graduate School of China Academy of Engineering Physics Haidian District Beijing100193 China Quantum Computing Center RIKEN Wakoshi Saitama351-0198 Japan Physics Department University of Michigan Ann ArborMI48109-1040 United States

The pseudomode framework provides an exact description of the dynamics of an open quantum system coupled to a non-Markovian environment. Using this framework, the influence of the environment on the system is studied in an equivalent model, where the open system is coupled to a finite number of unphysical pseudomodes that follow a time-local master equation. Building on the insight that this master equation does not need to conserve the hermiticity of the pseudomode state, we here ask for the most general conditions on the master equation that guarantee the correct reproduction of the system's original dynamics. We demonstrate that our generalized approach decreases the number of pseudomodes that are required to model, for example, underdamped environments at finite temperature. We also provide an unraveling of the master equation into quantum jump trajectories of non-Hermitian states, which further facilitates the utilization of the pseudomode technique for numerical calculations by enabling the use of easily parallelizable Monte Carlo simulations. Finally, we show that pseudomodes, despite their unphysical nature, provide a natural picture in which physical processes, such as the creation of system-bath correlations or the exchange of heat, can be studied. Hence, our results pave the way for future investigations of the system-environment interaction leading to a better understanding of open quantum systems far from the Markovian weak-coupling limit. Copyright © 2024, The Authors. All rights reserved.

关键词： Markov processes

Binding of the three-hadron DD∗K system from the lattice effective field theory

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arXiv 2024年

作者： Zhang, Zhenyu Hu, Xin-Yue He, Guangzhao Liu, Jun Shi, Jia-Ai Lu, Bing-Nan Wang, Qian Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear Science Southern Nuclear Science Computing Center South China Normal University Guangzhou510006 China Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter Institute of Quantum Matter South China Normal University Guangzhou510006 China Graduate School of China Academy of Engineering Physics Beijing100193 China Institute of Modern Physics Chinese Academy of Sciences Guangdong Province Huizhou516000 China

We employ the nuclear lattice effective field theory (NLEFT), an efficient tool for nuclear ab initio calculations, to solve the asymmetric multihadron systems. We take the DD∗K three-body system as an illustration to demonstrate the capability of the method. Here the two-body chiral interactions between D, D∗, and K are regulated with a soft lattice regulator and calibrated with the binding energies of the Tcc+, Ds∗0(2317), and Ds1(2460) molecular states. We then calculate the three-body binding energy using the NLEFT and analyze the systematic uncertainties due to the finite volume effects, the sliding cutoff, and the leading-order three-body forces. Even when the three-body interaction is repulsive (even as large as the infinite repulsive interaction), the three-body system has a bound state unambiguously with binding energy no larger than the Ds1(2460)D threshold. To check the renormalization group invariance of our framework, we extract the first excited state. We find that when the ground state is fixed, the first excited states with various cutoffs coincide with each other when the cubic size goes larger. In addition, the standard angular momentum and parity projection technique is implemented for the quantum numbers of the ground and excited states. We find that both of them are S-wave states with quantum number JP = 1−. Because the three-body state contains two charm quarks, it is easier to be detected in the Large Hadron Collider. Copyright © 2024, The Authors. All rights reserved.

关键词： Binding energy

AVTENet: Audio-Visual Transformer-based Ensemble Network Exploiting Multiple Experts for Video Deepfake Detection

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arXiv 2023年

作者： Hashmi, Ammarah Shahzad, Sahibzada Adil Lin, Chia-Wen Tsao, Yu Wang, Hsin-Min The Social Networks and Human-Centered Computing Program Taiwan International Graduate Program Academia Sinica Taipei11529 Taiwan The Institute of Information Systems and Applications National Tsing Hua University Hsinchu30013 Taiwan The Department of Computer Science National Chengchi University Taipei11605 Taiwan The Department of Electrical Engineering The Institute of Communications Engineering National Tsing Hua University Hsinchu300044 Taiwan The Research Center for Information Technology Innovation Academia Sinica Taipei11529 Taiwan The Institute of Information Science Academia Sinica Taipei11529 Taiwan

Forged content shared widely on social media platforms is a major social problem that requires increased regulation and poses new challenges to the research community. The recent proliferation of hyper-realistic deepfake videos has drawn attention to the threat of audio and visual forgeries. Most previous work on detecting AI-generated fake videos only utilizes visual modality or audio modality. While there are some methods in the literature that exploit audio and visual modalities to detect forged videos, they have not been comprehensively evaluated on multi-modal datasets of deepfake videos involving acoustic and visual manipulations. Moreover, these existing methods are mostly based on CNN and suffer from low detection accuracy. Inspired by the recent success of Transformer in various fields, to address the challenges posed by deepfake technology, in this paper, we propose an Audio-Visual Transformer-based Ensemble Network (AVTENet) framework that considers both acoustic manipulation and visual manipulation to achieve effective video forgery detection. Specifically, the proposed model integrates several purely transformer-based variants that capture video, audio, and audio-visual salient cues to reach a consensus in prediction. For evaluation, we use the recently released benchmark multi-modal audio-video FakeAVCeleb dataset. For a detailed analysis, we evaluate AVTENet, its variants, and several existing methods on multiple test sets of the FakeAVCeleb dataset. Experimental results show that our best model outperforms all existing methods and achieves state-of-the-art performance on Testset-I and Testset-II of the FakeAVCeleb dataset. © 2023, CC BY.

关键词： Statistical tests

A purified input-output pseudomode model for structured open quantum systems

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arXiv 2024年

作者： Liang, Pengfei Lambert, Neill Luo, Si Guo, Lingzhen Cirio, Mauro Center for Quantum Physics and Technologies School of Physical Science and Technology Inner Mongolia University Hohhot010021 China Graduate School of China Academy of Engineering Physics Haidian District Beijing100193 China Theoretical Physics Laboratory Cluster for Pioneering Research RIKEN Wakoshi Saitama351-0198 Japan Quantum Computing Center RIKEN Wakoshi Saitama351-0198 Japan Department of Chemistry Fudan University Shanghai200433 China Center for Joint Quantum Studies Department of Physics School of Science Tianjin University Tianjin300072 China

A full understanding of open quantum systems requires the characterization of both system and environmental properties. However, the complexity of the environmental statistics in the presence of strong system-bath hybridization and long memory effects usually prevents effective non-perturbative methods from going beyond the analysis of the reduced system dynamics. Here we present a model consisting of purified auxiliary bosonic modes to describe, alongside properties of the system, the dynamics of environmental observables for bosonic baths prepared in non-Gaussian initial states. We numerically exemplify this method by simulating non-Markovian multi-photon transfer processes on a coupled cavity waveguide system in the large time delay regime. Copyright © 2024, The Authors. All rights reserved.

关键词： Markov processes

Weak Devices Matter: Model Heterogeneity in Resource-Constrained Federated Learning

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Weak Devices Matter: Model Heterogeneity in Resource-Constra...

IEEE International Conference on Communications (ICC)

作者： Tzu–Hsuan Peng Cheng-Wei Huang Ai-Chun Pang Te-Chuan Chiu Department of Computer Science and Information Engineering National Taiwan University Taipei Taiwan R.O.C Graduate Institute of Networking and Multimedia National Taiwan University Taipei Taiwan R.O.C High Performance and Scientific Computing Center National Taiwan University Taipei Taiwan R.O.C Research Center for Information Technology Innovation Academia Sinica Taipei Taiwan R.O.C Department of Computer Science National Tsing Hua University Hsinchu Taiwan R.O.C

ISBN: (数字)9781728190549

ISBN: (纸本)9781728190556

Federated Learning (FL) is a promising framework for enabling edge intelligence while preserving privacy and enhancing communication efficiency. In real-world scenarios, limited and heterogeneous hardware resources among users threaten the overall training efficiency in FL. To address this issue, several model heterogeneity frameworks have emerged in recent years. However, existing studies primarily focus on mitigating idle times on powerful devices, overlooking the fact that strong devices may not always have a positive impact and can potentially become a burden instead. Furthermore, as the resource gap among clients widens or the number of weak devices increases, the model may be hindered by the influence of strong devices. Directly applying existing model heterogeneity frameworks leads to model performance degradation due to the neglect of contributions from weak devices. To make a performance breakthrough, we proposed a novel FL framework called Progressive Width Mixing (PWM), which extracts diverse features and balances the contribution of strong and weak devices and mitigates straggler effects under scenarios with various device distributions. To our best knowledge, we are the first model heterogeneity work that considered straggler effects from the weak devices' point of view. The experiments show that PWM maintains stability over different datasets and outperforms all baselines across various device distributions and non-IID scenarios. PWM makes a leap forward and surpasses all baselines by 7%, and mitigates the negative impact from the strong devices.

关键词： Performance evaluation Training Privacy Philosophical considerations Federated learning Pulse width modulation System recovery

GENESHIFT: IMPACT OF DIFFERENT SCENARIO SHIFT ON JAILBREAKING LLM

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arXiv 2025年

作者： Wu, Tianyi Xue, Zhiwei Liu, Yue Zhang, Jiaheng Hooi, Bryan Ng, See-Kiong Integrative Sciences and Engineering Programme NUS Graduate School National University of Singapore Singapore National University of Singapore Singapore Department of Computer Science School of Computing National University of Singapore Singapore

Jailbreak attacks, which aim to cause LLMs to perform unrestricted behaviors, have become a critical and challenging direction in AI safety. Despite achieving the promising attack success rate using dictionary-based evaluation, existing jailbreak attack methods fail to output detailed contents to satisfy the harmful request, leading to poor performance on GPT-based evaluation. To this end, we propose a black-box jailbreak attack termed GeneShift, by using a genetic algorithm to optimize the scenario shifts. Firstly, we observe that the malicious queries perform optimally under different scenario shifts. Based on it, we develop a genetic algorithm to evolve and select the hybrid of scenario shifts. It guides our method to elicit detailed and actionable harmful responses while keeping the seemingly benign facade, improving stealthiness. Extensive experiments demonstrate the superiority of GeneShift. Notably, GeneShift increases the jailbreak success rate from 0% to 60% when direct prompting alone would fail. We will open-source our code. © 2025, CC BY.

关键词： Genetic algorithms

Quantum-inspired algorithm applied to extreme learning

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arXiv 2022年

作者： Takeda, Iori Takahira, Souichi Mitarai, Kosuke Fujii, Keisuke Graduate School of Engineering Science Osaka University 1-3 Machikaneyama Toyonaka Osaka560-8531 Japan Center for Quantum Information and Quantum Biology Institute for Open and Transdisciplinary Research Initiatives Osaka University Japan Center for Quantum Computing RIKEN Saitama Wako351-0198 Japan

Quantum-inspired singular value decomposition (SVD) is a technique to perform SVD in logarithmic time with respect to the dimension of a matrix, given access to the matrix embedded in a segment-tree data structure. The speedup is possible through the efficient sampling of matrix elements according to their norms. Here, we apply it to extreme learning which is a machine learning framework that performs linear regression using random feature vectors generated through a random neural network. The extreme learning is suited for the application of quantum-inspired SVD in that it first requires transforming each data to a random feature during which we can construct the data structure with a logarithmic overhead with respect to the number of data. We implement the algorithm and observe that it works order-of-magnitude faster than the exact SVD when we use high-dimensional feature vectors. However, we also observe that, for random features generated by random neural networks, we can replace the norm-based sampling in the quantum-inspired algorithm with uniform sampling to obtain the same level of test accuracy due to the uniformity of the matrix in this case. The norm-based sampling becomes effective for more non-uniform matrices obtained by optimizing the feature mapping. It implies the non-uniformity of matrix elements is a key property of the quantum-inspired SVD. This work is a first step toward the practical application of the quantum-inspired algorithm. Copyright © 2022, The Authors. All rights reserved.

关键词： Singular value decomposition

Comparative study of decoding the surface code using simulated annealing under depolarizing noise

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arXiv 2023年

作者： Takeuchi, Yusaku Takada, Yugo Sakashita, Tatsuya Fujisaki, Jun Oshima, Hirotaka Sato, Shintaro Fujii, Keisuke Division of Advanced Electronics and Optical Science Department of Systems Innovation Graduate School of Engineering Science Osaka University Japan Graduate School of Engineering Science Osaka University 1-3 Machikaneyama Toyonaka Osaka560-8531 Japan Center for Quantum Information and Quantum Biology Osaka University Osaka560-0043 Japan Quantum Laboratory Fujitsu Research Fujitsu Limited 4-1-1 Kawasaki Kanagawa211-8588 Japan Fujitsu Quantum Computing Joint Research Division Center for Quantum Information and Quantum Biology Osaka University 1-2 Machikaneyama Toyonaka Osaka565-8531 Japan Center for Quantum Information and Quantum Biology Osaka University 560-0043 Japan Saitama Wako351-0198 Japan

We explored decoding methods for the surface code under depolarizing noise by mapping the problem into the Ising model optimization. We consider two kinds of mapping with and without a soft constraint and also various optimization solvers, including simulated annealing implemented on a CPU,"Fujitsu Digital Annealer" (DA), a hardware architecture specialized for the Ising problems, and CPLEX, an exact integer programming solver. We find that the proposed Ising-based decoding approaches provide higher accuracy compared to the minimum-weight perfect matching (MWPM) algorithm for depolarizing noise and comparable to minimum distance decoding using CPLEX. While decoding time is longer than MWPM when we compare it with a single core CPU, our method is amenable to parallelization and easy to implement on dedicated hardware, suggesting potential future speedups. Regarding the mapping methods to the Ising model with and without a soft constraint, the SA decoder yielded higher accuracy without a soft constraint. In contrast, the DA decoder shows less difference between the two mapping methods, which indicates that DA can find a better solution with smaller number of iterations even under the soft constraint. Our results are important for devising efficient and fast decoders feasible with quantum computer control devices. Copyright © 2023, The Authors. All rights reserved.

关键词： Simulated annealing