量子科技
量子科技是一个跨学科领域，涉及物理学、计算机科学、工程学和信息科学等多个学科。随着量子科技的不断进步，它有可能在未来几十年内彻底改变我们的技术景观。
相关预印本
Exciton Dressing by Extreme Nonlinear Magnons in a Layered Semiconductor
作者：Geoffrey M. Diederich;Mai Nguyen;John Cenker;Jordan Fonseca;Sinabu Pumulo;Youn Jue Bae;Daniel G. Chica;Xavier Roy;Xiaoyang Zhu;Di Xiao;Yafei Ren;Xiaodong Xu
摘要：Collective excitations presenting nonlinear dynamics are fundamental phenomena with broad applications. A prime example is nonlinear optics, where diverse frequency mixing processes are central to communication, sensing, wavelength conversion, and attosecond physics. Leveraging recent progress in van der Waals magnetic semiconductors, we demonstrate nonlinear opto-magnonic coupling by presenting exciton states dressed by up to 20 harmonics of magnons, resulting from their nonlinearities, in the layered antiferromagnetic semiconductor CrSBr. We also create tunable optical side bands from sum- and difference-frequency generation between two optically bright magnon modes under symmetry breaking magnetic fields. Moreover, the observed difference-frequency generation mode can be continuously tuned into resonance with one of the fundamental magnons, resulting in parametric amplification of magnons. These findings realize the modulation of the optical frequency exciton with the extreme nonlinearity of magnons at microwave frequencies, which could find applications in magnonics and hybrid quantum systems, and provide new avenues for implementing opto-magnonic devices.Experimental Measurement-Device-Independent Quantum Cryptographic Conferencing
作者：Yifeng Du;Yufeng Liu;Chengdong Yang;Xiaodong Zheng;Shining Zhu;Xiao-song Ma
摘要：Quantum cryptographic conferencing (QCC) allows sharing secret keys among multiple distant users and plays a crucial role in quantum networks. Due to the fragility and low generation rate of genuine multipartite entangled states required in QCC, realizing and extending QCC with the entanglement-based protocol is challenging. Measurement-device-independent QCC (MDI-QCC), which removes all detector side-channels, is a feasible long-distance quantum communication scheme to practically generate multipartite correlation with multiphoton projection measurement. Here we experimentally realize the three-user MDI-QCC protocol with four-intensity decoy-state method, in which we employ the polarization encoding and the Greenberger-Horne-Zeilinger (GHZ) state projection measurement. Our work demonstrates the experimental feasibility of the MDI-QCC, which lays the foundation for the future realization of quantum networks with multipartite communication tasks.Continuous-Variable Source-Independent Quantum Random Number Generator with a Single Phase-Insensitive Detector
作者：Hongyi Zhou
摘要：Quantum random number generators (QRNGs) harness quantum mechanical unpredictability to produce true randomness, which is crucial for cryptography and secure communications. Among various QRNGs, source-independent QRNGs (SI-QRNGs) relax the trust on the quantum source, allowing for flexible use of advanced detectors to achieve high randomness generation rates. Continuous-variable (CV) SI-QRNGs, in particular, hold promise for practical deployment due to their simplicity and randomness generation rates comparable to trusted-device QRNGs. In this work, we propose a novel CV-SI-QRNG scheme with a single phase-insensitive detector, and provide security proof based on semi-definite programming (SDP). We introduce a dimension reduction technique, which rigorously reduces an infinite-dimensional SDP problem to a finite-dimensional one, enabling efficient computation while maintaining valid randomness lower bound. We further validate our method through simulations. These results demonstrate the feasibility of our framework, paving the way for practical and simple SI-QRNG implementations.Continuous-Variable Multiplexed Quantum Repeater Networks
作者：Pei-Zhe Li;William J. Munro;Kae Nemoto;Nicoló Lo Piparo
摘要：Continuous-variable (CV) codes and their application in quantum communication have attracted increasing attention. In particular, one typical CV codes, cat-codes, has already been experimentally created using trapped atoms in cavities with relatively high fidelities. However, when these codes are used in a repeater protocol, the secret key rate (SKR) that can be extracted between two remote users is extremely low. Here we propose a quantum repeater protocol based on cat codes with a few quantum memories or graph states as additional resources. This allows us to considerably increase the secret key rate by several orders of magnitude. Our findings provide valuable insights for designing efficient quantum repeater systems, advancing the feasibility and performance of quantum communication over long distances.Uncorrectable-error-injection based reliable and secure quantum communication
作者：IlKwon Sohn;Boseon Kim;Kwangil Bae;Wooyeong Song;Chankyun Lee;Kabgyun Jeong;Wonhyuk Lee
摘要：Quantum networks aim to communicate distant quantum devices, such as quantum computers. In this context, a critical requirement is the secure and reliable transmission of arbitrary quantum states. Quantum teleportation is widely used to transmit arbitrary quantum states. However, it requires entanglement swapping and purification to distribute entanglements over long distances, introducing significant overhead and complexity. These challenges limit its practicality for real-world quantum communication networks. To address this limitation, we propose a novel scheme for directly transmitting quantum states encoded using error-correction codes. The proposed scheme leverages the robustness of quantum error correction codes to ensure secure and reliable quantum communication. By encoding quantum states with error-correction codes and strategically injecting uncorrectable errors, we enhance the security and reliability of the transmission process. Our approach reduces the overhead associated with entanglement distribution and provides a high tolerance for transmission errors. This study presents an advancement in practical and scalable quantum communication networks.Quantum Hamiltonian Descent for Graph Partition
作者：Jinglei Cheng;Ruilin Zhou;Yuhang Gan;Chen Qian;Junyu Liu
摘要：We introduce Quantum Hamiltonian Descent as a novel approach to solve the graph partition problem. By reformulating graph partition as a Quadratic Unconstrained Binary Optimization (QUBO) problem, we leverage QHD's quantum-inspired dynamics to identify optimal community structures. Our method implements a multi-level refinement strategy that alternates between QUBO formulation and QHD optimization to iteratively improve partition quality. Experimental results demonstrate that our QHD-based approach achieves superior modularity scores (up to 5.49\%) improvement with reduced computational overhead compared to traditional optimization methods. This work establishes QHD as an effective quantum-inspired framework for tackling graph partition challenges in large-scale networks.Capacity-Achieving Entanglement Purification Protocol for Pauli Dephasing Channel
作者：Ozlem Erkilic;Matthew S. Winnel;Aritra Das;Sebastian Kish;Ping Koy Lam;Jie Zhao;Syed M. Assad
摘要：Quantum communication facilitates the secure transmission of information and the distribution of entanglement, but the rates at which these tasks can be achieved are fundamentally constrained by the capacities of quantum channels. Although quantum repeaters typically enhance these rates by mitigating losses and noise, a simple entanglement swapping protocol via a central node is not effective against the Pauli dephasing channel due to the additional degradation introduced by Bell-state measurements. This highlights the importance of purifying distributed Bell states before performing entanglement swapping. In this work, we introduce an entanglement purification protocol assisted by two-way classical communication that not only purifies the states but also achieves the channel capacities. Our protocol uses an iterative process involving CNOT gates and Hadamard basis measurements, progressively increasing the fidelity of Bell states with each iteration. This process ensures that the resulting Bell pairs are perfect in the limit of many recursive iterations, making them ideal for use in quantum repeaters and for correcting dephasing errors in quantum computers. The explicit circuit we propose is versatile and applicable to any number of Bell pairs, offering a practical solution for mitigating decoherence in quantum networks and distributed quantum computing.Experimental optimal discrimination of $N$ states of a qubit with fixed rates of inconclusive outcomes
作者：L. F. Melo;M. A. Solís-Prosser;O. Jiménez;A. Delgado;L. Neves
摘要：In a general optimized measurement scheme for discriminating between nonorthogonal quantum states, the error rate is minimized under the constraint of a fixed rate of inconclusive outcomes (FRIO). This so-called optimal FRIO measurement encompasses the standard and well known minimum-error and optimal unambiguous (or maximum-confidence) discrimination strategies as particular cases. Here, we experimentally demonstrate the optimal FRIO discrimination between $N=2,3,5,$ and $7$ equally likely symmetric states of a qubit encoded in photonic path modes. Our implementation consists of applying a probabilistic quantum map which increases the distinguishability between the inputs in a controlled way, followed by a minimum-error measurement on the successfully transformed outputs. The results obtained corroborate this two-step approach and, in our experimental scheme, it can be straightforwardly extended to higher dimensions. The optimized measurement demonstrated here will be useful for quantum communication scenarios where the error rate and the inconclusive rate must be kept below the levels provided by the respective standard strategies.Independent Optical Frequency Combs Powered 546 km Field Test of Twin-Field Quantum Key Distribution
作者：Lai Zhou;Jinping Lin;Chengfang Ge;Yuanbin Fan;Zhiliang Yuan;Hao Dong;Yang Liu;Di Ma;Jiu-Peng Chen;Cong Jiang;Xiang-Bin Wang;Li-Xing You;Qiang Zhang;Jian-Wei Pan
摘要：Owing to its repeater-like rate-loss scaling, twin-field quantum key distribution (TF-QKD) has repeatedly exhibited in laboratory its superiority for secure communication over record fiber lengths. Field trials pose a new set of challenges however, which must be addressed before the technology's roll-out into real-world. Here, we verify in field the viability of using independent optical frequency combs -- installed at sites separated by a straight-line distance of 300~km -- to achieve a versatile TF-QKD setup that has no need for optical frequency dissemination and thus enables an open and network-friendly fiber configuration. Over 546 and 603 km symmetric links, we record a finite-size secure key rate (SKR) of 0.53~bit/s and an asymptotic SKR of 0.12 bit/s, respectively. Of practical importance, the setup is demonstrated to support 44~km fiber asymmetry in the 452 km link. Our work marks an important step towards incorporation of long-haul fiber links into large quantum networks.Gravitational Lensing in the Kerr Spacetime: An Analytic Approach for Light and High-Frequency Gravitational Waves
作者：Torben C. Frost
摘要：The Kerr spacetime is one of the most widely known solutions to Einstein's vacuum field equations and is commonly used to describe a black hole with mass $m$ and spin $a$. Astrophysical observations in the electromagnetic spectrum as well as detected gravitational wave signals indicate that it can be used to describe the spacetime around candidates for rotating black holes. While the geodesic structure of the Kerr spacetime is already well known for decades, using exact analytic solutions to the equations of motion for applications to astrophysical problems has only attracted attention relatively recently. Here, these applications mainly focus on predicting observations for the shadow, the photon rings, and characteristic structures in the accretion disk. Using the exact analytic solutions to investigate exact gravitational lensing of light and gravitational waves emitted by sources outside the accretion disk has only received limited attention so far. Therefore, the focus of this paper will be to address this question. For this purpose we assume that we have a standard observer in the domain of outer communication. We introduce a local orthonormal tetrad to relate the constants of motion of light rays and high-frequency gravitational waves detected by the observer to latitude-longitude coordinates on the observer's celestial sphere. In this parameterisation we derive the radius coordinates of the photon orbits and their latitudinal projections onto the observer's celestial sphere as functions of the celestial longitude. We use the latitude-longitude coordinates to classify the different types of motion, and solve the equations of motion analytically using elementary and Jacobi's elliptic functions as well as Legendre's elliptic integrals. We use the analytic solutions to write down an exact lens equation, and to calculate the redshift and the travel time.Transforming the Hybrid Cloud for Emerging AI Workloads
作者：Deming Chen;Alaa Youssef;Ruchi Pendse;André Schleife;Bryan K. Clark;Hendrik Hamann;Jingrui He;Teodoro Laino;Lav Varshney;Yuxiong Wang;Avirup Sil;Reyhaneh Jabbarvand;Tianyin Xu;Volodymyr Kindratenko;Carlos Costa;Sarita Adve;Charith Mendis;Minjia Zhang;Santiago Núñez-Corrales;Raghu Ganti;Mudhakar Srivatsa;Nam Sung Kim;Josep Torrellas;Jian Huang;Seetharami Seelam
摘要：This white paper, developed through close collaboration between IBM Research and UIUC researchers within the IIDAI Institute, envisions transforming hybrid cloud systems to meet the growing complexity of AI workloads through innovative, full-stack co-design approaches, emphasizing usability, manageability, affordability, adaptability, efficiency, and scalability. By integrating cutting-edge technologies such as generative and agentic AI, cross-layer automation and optimization, unified control plane, and composable and adaptive system architecture, the proposed framework addresses critical challenges in energy efficiency, performance, and cost-effectiveness. Incorporating quantum computing as it matures will enable quantum-accelerated simulations for materials science, climate modeling, and other high-impact domains. Collaborative efforts between academia and industry are central to this vision, driving advancements in foundation models for material design and climate solutions, scalable multimodal data processing, and enhanced physics-based AI emulators for applications like weather forecasting and carbon sequestration. Research priorities include advancing AI agentic systems, LLM as an Abstraction (LLMaaA), AI model optimization and unified abstractions across heterogeneous infrastructure, end-to-end edge-cloud transformation, efficient programming model, middleware and platform, secure infrastructure, application-adaptive cloud systems, and new quantum-classical collaborative workflows. These ideas and solutions encompass both theoretical and practical research questions, requiring coordinated input and support from the research community. This joint initiative aims to establish hybrid clouds as secure, efficient, and sustainable platforms, fostering breakthroughs in AI-driven applications and scientific discovery across academia, industry, and society.Enhancing Transportation Cyber-Physical Systems Security: A Shift to Post-Quantum Cryptography
作者：Abdullah Al Mamun;Akid Abrar;Mizanur Rahman;M Sabbir Salek;Mashrur Chowdhury
摘要：The rise of quantum computing threatens traditional cryptographic algorithms that secure Transportation Cyber-Physical Systems (TCPS). Shor's algorithm poses a significant threat to RSA and ECC, while Grover's algorithm reduces the security of symmetric encryption schemes, such as AES. The objective of this paper is to underscore the urgency of transitioning to post-quantum cryptography (PQC) to mitigate these risks in TCPS by analyzing the vulnerabilities of traditional cryptographic schemes and the applicability of standardized PQC schemes in TCPS. We analyzed vulnerabilities in traditional cryptography against quantum attacks and reviewed the applicability of NIST-standardized PQC schemes, including CRYSTALS-Kyber, CRYSTALS-Dilithium, and SPHINCS+, in TCPS. We conducted a case study to analyze the vulnerabilities of a TCPS application from the Architecture Reference for Cooperative and Intelligent Transportation (ARC-IT) service package, i.e., Electronic Toll Collection, leveraging the Microsoft Threat Modeling tool. This case study highlights the cryptographic vulnerabilities of a TCPS application and presents how PQC can effectively counter these threats. Additionally, we evaluated CRYSTALS-Kyber's performance across wired and wireless TCPS data communication scenarios. While CRYSTALS-Kyber proves effective in securing TCPS applications over high-bandwidth, low-latency Ethernet networks, our analysis highlights challenges in meeting the stringent latency requirements of safety-critical wireless applications within TCPS. Future research should focus on developing lightweight PQC solutions and hybrid schemes that integrate traditional and PQC algorithms, to enhance compatibility, scalability, and real-time performance, ensuring robust protection against emerging quantum threats in TCPS.Quantum Gravity, Hydrodynamics and Emergent Cosmology: A Collection of Perspectives
作者：Jibril Ben Achour;Dario Benedetti;Martin Bojowald;Robert Brandenberger;Salvatore Butera;Renata Ferrero;Flaminia Giacomini;Kristina Giesel;Christophe Goeller;Tobias Haas;Philipp A. Höhn;Joshua Kirklin;Luca Marchetti;Daniele Oriti;Roberto Percacci;Antonio D. Pereira;Andreas G. A. Pithis;Mairi Sakellariadou;Sebastian Steinhaus;Johannes Thürigen
摘要：This collection of perspective pieces captures recent advancements and reflections from a dynamic research community dedicated to bridging quantum gravity, hydrodynamics, and emergent cosmology. It explores four key research areas: (a) the interplay between hydrodynamics and cosmology, including analog gravity systems; (b) phase transitions, continuum limits and emergent geometry in quantum gravity; (c) relational perspectives in gravity and quantum gravity; and (d) the emergence of cosmological models rooted in quantum gravity frameworks. Each contribution presents the distinct perspectives of its respective authors. Additionally, the introduction by the editors proposes an integrative view, suggesting how these thematic units could serve as foundational pillars for a novel theoretical cosmology framework termed "hydrodynamics on superspace".Universal programmable waveguide arrays
作者：Akram Youssry;Alberto Peruzzo
摘要：Implementing arbitrary unitary transformations is crucial for applications in quantum computing, signal processing, and machine learning. Unitaries govern quantum state evolution, enabling reversible transformations critical in quantum tasks like cryptography and simulation and playing key roles in classical domains such as dimensionality reduction and signal compression. Integrated optical waveguide arrays have emerged as a promising platform for these transformations, offering scalability for both quantum and classical systems. However, scalable and efficient methods for implementing arbitrary unitaries remain challenging. Here, we present a theoretical framework for realizing arbitrary unitary matrices through programmable waveguide arrays (PWAs). We provide a mathematical proof demonstrating that cascaded PWAs can implement any unitary matrix within practical constraints, along with a numerical optimization method for customized PWA designs. Our results establish PWAs as a universal and scalable architecture for quantum photonic computing, effectively bridging quantum and classical applications, and positioning PWAs as an enabling technology for advancements in quantum simulation, machine learning, secure communication, and signal processing.Quantum teleportation with dissimilar quantum dots over a hybrid quantum network
作者：Alessandro Laneve;Giuseppe Ronco;Mattia Beccaceci;Paolo Barigelli;Francesco Salusti;Nicolas Claro-Rodriguez;Giorgio De Pascalis;Alessia Suprano;Leone Chiaudano;Eva Schöll;Lukas Hanschke;Tobias M. Krieger;Quirin Buchinger;Saimon F. Covre da Silva;Julia Neuwirth;Sandra Stroj;Sven Höfling;Tobias Huber-Loyola;Mario A. Usuga Castaneda;Gonzalo Carvacho;Nicolò Spagnolo;Michele B. Rota;Francesco Basso Basset;Armando Rastelli;Fabio Sciarrino
摘要：Photonic quantum information processing in metropolitan quantum networks lays the foundation for cloud quantum computing [1, 2], secure communication [3, 4], and the realization of a global quantum internet [5, 6]. This paradigm shift requires on-demand and high-rate generation of flying qubits and their quantum state teleportation over long distances [7]. Despite the last decade has witnessed an impressive progress in the performances of deterministic photon sources [8-11], the exploitation of distinct quantum emitters to implement all-photonic quantum teleportation among distant parties has remained elusive. Here, we overcome this challenge by using dissimilar quantum dots whose electronic and optical properties are engineered by light-matter interaction [12], multi-axial strain [13] and magnetic fields [14] so as to make them suitable for the teleportation of polarization qubits. This is demonstrated in a hybrid quantum network harnessing both fiber connections and 270 m free-space optical link connecting two buildings of the University campus in the center of Rome. The protocol exploits GPS-assisted synchronization, ultra-fast single photon detectors as well as stabilization systems that compensate for atmospheric turbulence. The achieved teleportation state fidelity reaches up to 82+-1%, above the classical limit by more than 10 standard deviations. Our field demonstration of all-photonic quantum teleportation opens a new route to implement solid-state based quantum relays and builds the foundation for practical quantum networks.