arXiv - PHYS - Quantum Physics最新文献_第9页

Near-optimal coherent state discrimination via continuously labelled non-Gaussian measurements 通过连续标记的非高斯测量实现近乎最佳的相干状态判别

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.08032

James Moran, Spiros Kechrimparis, Hyukjoon Kwon

{"title":"Near-optimal coherent state discrimination via continuously labelled non-Gaussian measurements","authors":"James Moran, Spiros Kechrimparis, Hyukjoon Kwon","doi":"arxiv-2409.08032","DOIUrl":"https://doi.org/arxiv-2409.08032","url":null,"abstract":"Quantum state discrimination plays a central role in quantum information and\u0000communication. For the discrimination of optical quantum states, the two most\u0000widely adopted measurement techniques are photon detection, which produces\u0000discrete outcomes, and homodyne detection, which produces continuous outcomes.\u0000While various protocols using photon detection have been proposed for optimal\u0000and near-optimal discrimination between two coherent states, homodyne detection\u0000is known to have higher error rates, with its performance often referred to as\u0000the Gaussian limit. In this work, we demonstrate that, despite the fundamental\u0000differences between discretely labelled and continuously labelled measurements,\u0000continuously labelled non-Gaussian measurements can also achieve near-optimal\u0000coherent state discrimination. We explicitly design two coherent state\u0000discrimination protocols based on non-Gaussian unitary operations combined with\u0000homodyne detection and orthogonal polynomials, which surpass the Gaussian\u0000limit. Our results show that photon detection is not required for near-optimal\u0000coherent state discrimination and that we can achieve error rates close to the\u0000Helstrom bound at low energies with continuously labelled measurements. We also\u0000find that our schemes maintain an advantage over the photon detection-based\u0000Kennedy receiver for a moderate range of coherent state amplitudes.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robust and bright polarization-entangled photon sources exploiting non-critical phase matching without periodic poling 无需周期性极化即可利用非临界相位匹配的稳健而明亮的偏振纠缠光子源

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07673

Ilhwan Kim, Yosep Kim, Yong-Su Kim, Kwang Jo Lee, Hyang-Tag Lim

{"title":"Robust and bright polarization-entangled photon sources exploiting non-critical phase matching without periodic poling","authors":"Ilhwan Kim, Yosep Kim, Yong-Su Kim, Kwang Jo Lee, Hyang-Tag Lim","doi":"arxiv-2409.07673","DOIUrl":"https://doi.org/arxiv-2409.07673","url":null,"abstract":"Entangled photon sources are essential for quantum information applications,\u0000including quantum computation, quantum communication, and quantum metrology.\u0000Periodically poled (PP) crystals are commonly used to generate bright photon\u0000sources through quasi-phase matching. However, fabricating uniform micron-scale\u0000periodic structures poses significant technical difficulties, typically\u0000limiting the crystal thickness to less than a millimeter. Here, we adopt\u0000non-critical phase matching to produce a robust and bright\u0000polarization-entangled photon source based on a Sagnac interferometer. This\u0000method is tolerant of variations in pump incidence angles and temperature, and\u0000theoretically offers about a 2.5-fold brightness enhancement compared to\u0000quasi-phase matching. Additionally, the absence of periodic poling allows for a\u0000larger crystal cross-section. Using a bulk KTP crystal without a PP structure,\u0000we experimentally produce the four Bell states with a brightness of 25.1\u0000kHz/mW, achieving purity, concurrence, and fidelity values close to 0.99. We\u0000believe our scheme will serve as a key building block for scalable and\u0000practical photonic quantum information applications.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Capturing magic angles in twisted bilayer graphene from information theory markers 从信息论标记捕捉扭曲双层石墨烯中的神奇角度

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07935

Manuel Calixto, Alberto Mayorgas, Octavio Castaños

引用次数: 0

Low-overhead magic state distillation with color codes 带颜色代码的低成本魔态蒸馏

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07707

Seok-Hyung Lee, Felix Thomsen, Nicholas Fazio, Benjamin J. Brown, Stephen D. Bartlett

{"title":"Low-overhead magic state distillation with color codes","authors":"Seok-Hyung Lee, Felix Thomsen, Nicholas Fazio, Benjamin J. Brown, Stephen D. Bartlett","doi":"arxiv-2409.07707","DOIUrl":"https://doi.org/arxiv-2409.07707","url":null,"abstract":"Fault-tolerant implementation of non-Clifford gates is a major challenge for\u0000achieving universal fault-tolerant quantum computing with quantum\u0000error-correcting codes. Magic state distillation is the most well-studied\u0000method for this but requires significant resources. Hence, it is crucial to\u0000tailor and optimize magic state distillation for specific codes from both\u0000logical- and physical-level perspectives. In this work, we perform such\u0000optimization for two-dimensional color codes, which are promising due to their\u0000higher encoding rates compared to surface codes, transversal implementation of\u0000Clifford gates, and efficient lattice surgery. We propose two distillation\u0000schemes based on the 15-to-1 distillation circuit and lattice surgery, which\u0000differ in their methods for handling faulty rotations. Our first scheme uses\u0000faulty T-measurement, offering resource efficiency when the target infidelity\u0000is above a certain threshold ($sim 35p^3$ for physical error rate $p$). To\u0000achieve lower infidelities while maintaining resource efficiency, our second\u0000scheme exploits a distillation-free fault-tolerant magic state preparation\u0000protocol, achieving significantly lower infidelities (e.g., $sim 10^{-19}$ for\u0000$p = 10^{-4}$) than the first scheme. Notably, our schemes outperform the best\u0000existing magic state distillation methods for color codes by up to about two\u0000orders of magnitude in resource costs for a given achievable target infidelity.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulating anharmonic vibrational polaritons beyond the long wavelength approximation 超越长波长近似模拟非谐振动极化子

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07992

Dipti Jasrasaria, Arkajit Mandal, David R. Reichman, Timothy C. Berkelbach

引用次数: 0

Quantum Information Resources in Spin-1 Heisenberg Dimer Systems 自旋-1 海森堡二聚体系统中的量子信息资源

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.08082

Fadwa Benabdallah, M. Y. Abd-Rabbou, Mohammed Daoud, Saeed Haddadi

{"title":"Quantum Information Resources in Spin-1 Heisenberg Dimer Systems","authors":"Fadwa Benabdallah, M. Y. Abd-Rabbou, Mohammed Daoud, Saeed Haddadi","doi":"arxiv-2409.08082","DOIUrl":"https://doi.org/arxiv-2409.08082","url":null,"abstract":"We explore the quantum information resources within bipartite pure and mixed\u0000states of the quantum spin-1 Heisenberg dimer system, considering some\u0000interesting factors such as the $l_{1}$-norm of quantum coherence, relative\u0000coherence, entanglement, and steering, influenced by the magnetic field and\u0000uniaxial single-ion anisotropy. Through a thorough investigation, we derive the\u0000system's density operator at thermal equilibrium and establish a mathematical\u0000framework for analyzing quantum correlation metrics. Our results unveil the\u0000system's behavior at absolute zero temperature, revealing quantum\u0000antiferromagnetic, ferromagnetic, and ferrimagnetic phase transitions governed\u0000by the magnetic field and anisotropy parameters. We further observe\u0000temperature's role in transitioning the system towards classical states,\u0000impacting coherence, entanglement, and steering differently. Notably, we find\u0000that increasing the exchange anisotropy parameter can reinforce quantum\u0000correlations while adjusting the uniaxial single-ion anisotropy parameter\u0000influences the system's quantumness, particularly when positive. Some\u0000recommendations to maximize quantum coherence, entanglement, and steering\u0000involve temperature reduction, increasing the exchange anisotropy parameter,\u0000and carefully managing the magnetic field and uniaxial single-ion anisotropy\u0000parameter, highlighting the intricate interplay between these factors in\u0000maintaining the system's quantum properties.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Towards Scalable Quantum Key Distribution: A Machine Learning-Based Cascade Protocol Approach 实现可扩展的量子密钥分发：基于机器学习的级联协议方法

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.08038

Hasan Abbas Al-Mohammed, Saif Al-Kuwari, Hashir Kuniyil, Ahmed Farouk

{"title":"Towards Scalable Quantum Key Distribution: A Machine Learning-Based Cascade Protocol Approach","authors":"Hasan Abbas Al-Mohammed, Saif Al-Kuwari, Hashir Kuniyil, Ahmed Farouk","doi":"arxiv-2409.08038","DOIUrl":"https://doi.org/arxiv-2409.08038","url":null,"abstract":"Quantum Key Distribution (QKD) is a pivotal technology in the quest for\u0000secure communication, harnessing the power of quantum mechanics to ensure\u0000robust data protection. However, scaling QKD to meet the demands of high-speed,\u0000real-world applications remains a significant challenge. Traditional key rate\u0000determination methods, dependent on complex mathematical models, often fall\u0000short in efficiency and scalability. In this paper, we propose an approach that\u0000involves integrating machine learning (ML) techniques with the Cascade error\u0000correction protocol to enhance the scalability and efficiency of QKD systems.\u0000Our ML-based approach utilizes an autoencoder framework to predict the Quantum\u0000Bit Error Rate (QBER) and final key length with over 99% accuracy. This method\u0000significantly reduces error correction time, maintaining a consistently low\u0000computation time even with large input sizes, such as data rates up to 156\u0000Mbps. In contrast, traditional methods exhibit exponentially increasing\u0000computation times as input sizes grow, highlighting the superior scalability of\u0000our ML-based solution. Through comprehensive simulations, we demonstrate that\u0000our method not only accelerates the error correction process but also optimizes\u0000resource utilization, making it more cost-effective and practical for\u0000real-world deployment. The Cascade protocol's integration further enhances\u0000system security by dynamically adjusting error correction based on real-time\u0000QBER observations, providing robust protection against potential eavesdropping. Our research establishes a new benchmark for scalable, high-throughput QKD\u0000systems, proving that machine learning can significantly advance the field of\u0000quantum cryptography. This work continues the evolution towards truly scalable\u0000quantum communication.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

C3-VQA: Cryogenic Counter-based Co-processor for Variational Quantum Algorithms C3-VQA：基于低温计数器的变分量子算法协处理器

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07847

Yosuke Ueno, Satoshi Imamura, Yuna Tomida, Teruo Tanimoto, Masamitsu Tanaka, Yutaka Tabuchi, Koji Inoue, Hiroshi Nakamura

{"title":"C3-VQA: Cryogenic Counter-based Co-processor for Variational Quantum Algorithms","authors":"Yosuke Ueno, Satoshi Imamura, Yuna Tomida, Teruo Tanimoto, Masamitsu Tanaka, Yutaka Tabuchi, Koji Inoue, Hiroshi Nakamura","doi":"arxiv-2409.07847","DOIUrl":"https://doi.org/arxiv-2409.07847","url":null,"abstract":"Cryogenic quantum computers play a leading role in demonstrating quantum\u0000advantage. Given the severe constraints on the cooling capacity in cryogenic\u0000environments, thermal design is crucial for the scalability of these computers.\u0000The sources of heat dissipation include passive inflow via inter-temperature\u0000wires and the power consumption of components located in the cryostat, such as\u0000wire amplifiers and quantum-classical interfaces. Thus, a critical challenge is\u0000to reduce the number of wires by reducing the required inter-temperature\u0000bandwidth while maintaining minimal additional power consumption in the\u0000cryostat. One solution to address this challenge is near-data processing using\u0000ultra-low-power computational logic within the cryostat. Based on the workload\u0000analysis and domain-specific system design focused on Variational Quantum\u0000Algorithms (VQAs), we propose the Cryogenic Counter-based Co-processor for VQAs\u0000(C3-VQA) to enhance the design scalability of cryogenic quantum computers under\u0000the thermal constraint. The C3-VQA utilizes single-flux-quantum logic, which is\u0000an ultra-low-power superconducting digital circuit that operates at the 4 K\u0000environment. The C3-VQA precomputes a part of the expectation value\u0000calculations for VQAs and buffers intermediate values using simple bit\u0000operation units and counters in the cryostat, thereby reducing the required\u0000inter-temperature bandwidth with small additional power consumption.\u0000Consequently, the C3-VQA reduces the number of wires, leading to a reduction in\u0000the total heat dissipation in the cryostat. Our evaluation shows that the\u0000C3-VQA reduces the total heat dissipation at the 4 K stage by 30% and 81% under\u0000sequential-shot and parallel-shot execution scenarios, respectively.\u0000Furthermore, a case study in quantum chemistry shows that the C3-VQA reduces\u0000total heat dissipation by 87% with a 10,000-qubit system.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exotic localization for the two body bound states in the non-reciprocal Hubbard model 非互惠哈伯德模型中两体束缚态的异域定位

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07883

Huan-Yu Wang, Ji Li, Wu-Ming Liu, Lin Wen, Xiao-Fei Zhang

{"title":"Exotic localization for the two body bound states in the non-reciprocal Hubbard model","authors":"Huan-Yu Wang, Ji Li, Wu-Ming Liu, Lin Wen, Xiao-Fei Zhang","doi":"arxiv-2409.07883","DOIUrl":"https://doi.org/arxiv-2409.07883","url":null,"abstract":"We investigate the localization behavior of two-body Hubbard model in the\u0000presence of non-reciprocal tunneling, where the interaction induced Anderson\u0000localization competes with the non-Hermitian skin effects and gives rise to\u0000diverse patterns of density profiles. Here, we present the non-Hermitian bound\u0000states obtained with the center of mass methods in the conditions of strong\u0000repulsive interaction, where a faded diagonal line localization is observed.\u0000While for the continuum limit, the non-Hermitian skin effects are manifested by\u0000non-zero windings of the eigen-energy spectrum. For the moderate interaction\u0000strength, it is illustrated that the system possesses multiple Lyapunov\u0000exponents due to the competence above and as a consequence, in sharp contrast\u0000to the corner localization, the two-body non-Hermitian continuum states can\u0000exhibit multiple localization center. By further including two-photon\u0000tunneling, topological nontrivial photon bound pairs can be obtained. Finally,\u0000the experimental simulations are proposed based on the platforms of the\u0000electrical circuit lattices.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wavevector-resolved polarization entanglement from radiative cascades 来自辐射级联的波矢分辨偏振纠缠

arXiv - PHYS - Quantum Physics Pub Date : 2024-09-12 DOI: arxiv-2409.07875

Alessandro Laneve, Michele B. Rota, Francesco Basso Basset, Mattia Beccaceci, Valerio Villari, Thomas Oberleitner, Yorick Reum, Tobias M. Krieger, Quirin Buchinger, Saimon F. Covre da Silva, Andreas Pfenning, Sandra Stroj, Sven Höfling, Armando Rastelli, Tobias Huber-Loyola, Rinaldo Trotta

{"title":"Wavevector-resolved polarization entanglement from radiative cascades","authors":"Alessandro Laneve, Michele B. Rota, Francesco Basso Basset, Mattia Beccaceci, Valerio Villari, Thomas Oberleitner, Yorick Reum, Tobias M. Krieger, Quirin Buchinger, Saimon F. Covre da Silva, Andreas Pfenning, Sandra Stroj, Sven Höfling, Armando Rastelli, Tobias Huber-Loyola, Rinaldo Trotta","doi":"arxiv-2409.07875","DOIUrl":"https://doi.org/arxiv-2409.07875","url":null,"abstract":"The generation of entangled photons from radiative cascades has enabled\u0000milestone experiments in quantum information science with several applications\u0000in photonic quantum technologies. Significant efforts are being devoted to\u0000pushing the performances of near-deterministic entangled-photon sources based\u0000on single quantum emitters often embedded in photonic cavities, so to boost the\u0000flux of photon pairs. The general postulate is that the emitter generates\u0000photons in a nearly maximally entangled state of polarization, ready for\u0000application purposes. Here, we demonstrate that this assumption is unjustified.\u0000We show that in radiative cascades there exists an interplay between photon\u0000polarization and emission wavevector, strongly affecting quantum correlations\u0000when emitters are embedded in micro-cavities. We discuss how the polarization\u0000entanglement of photon pairs from a biexciton-exciton cascade in quantum dots\u0000strongly depends on their propagation wavevector, and it can even vanish for\u0000large emission angles. Our experimental results, backed by theoretical\u0000modelling, yield a brand-new understanding of cascaded emission for various\u0000quantum emitters. In addition, our model provides quantitative guidelines for\u0000designing optical microcavities that retain both a high degree of entanglement\u0000and collection efficiency, moving the community one step further towards an\u0000ideal source of entangled photons for quantum technologies.","PeriodicalId":501226,"journal":{"name":"arXiv - PHYS - Quantum Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142202252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0