Article
Computer Science, Information Systems
Uzi Pereg, Christian Deppe, Holger Boche
Summary: In this study, a new model of unreliable entanglement assistance is introduced for communication systems. The sender is unaware of whether the entangled photon has reached the receiver, while the receiver knows the success of entanglement generation. The effective transmission rate is adapted based on the assistance status in this model.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Physics, Multidisciplinary
Assaf Ben-Yishai, Young-Han Kim, Rotem Oshman, Ofer Shayevitz
Summary: The study shows that in simulating finite-state protocols, all two-state protocols and certain rich families of finite-state protocols can be successfully simulated at the Shannon capacity.
Article
Physics, Multidisciplinary
Zhang-Dong Ye, Dong Pan, Zhen Sun, Chun-Guang Du, Liu-Guo Yin, Gui-Lu Long
Summary: Quantum secure direct communication has made great strides in theory and experiment in the past two decades, but its security analysis is still in its infancy. Practical problems such as detector efficiency mismatch, side-channel effect, and source imperfection are driving the need for a more impeccable solution. A new framework driven by numerics and proposed optimizing methods show promise for advancing the field.
FRONTIERS OF PHYSICS
(2021)
Article
Computer Science, Information Systems
Ivan B. Djordjevic
Summary: Entanglement assisted communication is advocated as an alternative to classical communication for significant improvement in channel capacity, but under imperfect pre-shared entanglement distribution, it may be inferior to classical communication depending on the parameters of the distribution channel. However, there are conditions where entanglement assistance can still provide an advantage over classical communication.
Article
Computer Science, Information Systems
Omar Fawzi, Ala Shayeghi, Hoang Ta
Summary: This paper discusses optimal rates for achieving an information processing task in quantum tasks and how to compute these quantities using regularized information measures by exploiting symmetries. It introduces a method of obtaining a hierarchy of semidefinite programming bounds and provides a general procedure for efficiently bounding regularized quantities of quantum channels.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Engineering, Electrical & Electronic
Carl Pfeiffer, Bae-Ian Wu
Summary: The article derives a simplified expression for the maximum data rate that can be reliably communicated through a narrowband, resonant antenna with a Lorentzian frequency response. Both transmit and receive cases are considered. The study shows that resonant antennas handle different data rates on receive than transmit due to filtering out external noise but adding their own loss-related noise. It also demonstrates how adding loss, an impedance mismatch, or a matching network can increase channel capacity by widening the resonant bandwidth at the expense of reduced signal strength.
IEEE TRANSACTIONS ON COMMUNICATIONS
(2023)
Article
Automation & Control Systems
Runyue Fang, Dequan Li, Xiuyu Shen
Summary: This paper proposes a distributed online adaptive subgradient learning algorithm called DAdaxBound, which can effectively handle optimization problems in time-varying networks and has good performance on convex and potentially nonsmooth objective functions.
IET CONTROL THEORY AND APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Ivan Djordjevic
Summary: This paper introduces several low-complexity quantum receivers that outperform previously proposed receivers using optical parametric amplifiers as building blocks. Through simulations, it is demonstrated that the proposed EA schemes with Gaussian modulation and low-complexity joint receivers can significantly outperform both the Holevo capacity and classical homodyne and heterodyne channel capacities.
IEEE PHOTONICS JOURNAL
(2021)
Article
Computer Science, Information Systems
Ivan B. Djordjevic
Summary: The proposed entanglement-assisted communication system using optical phase-conjugation on the transmitter side outperforms classical communication in low-brightness and highly noisy scenarios, with a significantly higher capacity compared to other existing methods. The performance improvement is particularly notable when employing a classical coherent detection scheme for demodulation.
Article
Quantum Science & Technology
Armin Tavakoli, Jef Pauwels, Erik Woodhead, Stefano Pironio
Summary: This study investigates correlations between Alice and Bob in communication scenarios where prior entanglement can be shared. The research explores protocols involving entangled states and the potential for increased communication capacity. The findings show how correlations can be characterized through semidefinite programming relaxations and introduce alternative relaxation hierarchies for computational efficiency. Additionally, device-independent tests for classical and quantum systems are introduced, along with establishing relationships between communication with and without entanglement as resources for creating correlations.
Article
Computer Science, Information Systems
Uzi Pereg, Christian Deppe, Holger Boche
Summary: This study focuses on communication over a quantum channel that depends on a quantum state, where the encoder has channel side information and is required to mask information on the quantum channel state from the decoder. A full characterization is established for the entanglement-assisted masking equivocation region, and a regularized formula is given for the quantum capacity-leakage function without assistance. For Hadamard channels without assistance, single-letter inner and outer bounds are derived, coinciding in the standard case of a channel that does not depend on a state.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2021)
Article
Optics
Jeffrey H. Shapiro
Summary: This research proves that the error probability of a coherent-state radar is within a factor of two of the best possible quantum performance under certain conditions. However, first-photon radars can surpass this limit and achieve better performance.
Article
Optics
M. Vaisakh, Ram Krishna Patra, Mukta Janpandit, Samrat Sen, Manik Banik, Anubhav Chaturvedi
Summary: The study introduces a generalized random access code task where the receiver aims to retrieve randomly chosen functions of the sender's input string, in addition to individual input bits. The performance of classical, quantum, and entanglement assisted classical communication protocols for this task is investigated and bounded, revealing characteristic properties that deviate from standard random access codes.
Article
Chemistry, Multidisciplinary
Anna M. Krol, Aritra Sarkar, Imran Ashraf, Zaid Al-Ars, Koen Bertels
Summary: Unitary decomposition is an important method for mapping quantum algorithms to quantum gates, and efficient implementation is crucial for executing these algorithms on existing quantum computers. Our implementation, based on Quantum Shannon Decomposition, generates shorter circuits and is significantly faster compared to other similar tools.
APPLIED SCIENCES-BASEL
(2022)
Article
Management
Kanglin Liu, Changchun Liu, Xi Xiang, Zhili Tian
Summary: This paper focuses on locating testing facilities to meet varying demand caused by pandemics. A two-phase optimization framework is proposed to locate facilities and adjust capacity during emergencies. Online convex optimization and online gradient descent algorithms are used to solve the problem. A case study verifies the effectiveness of the framework.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2023)
Article
Physics, Mathematical
Hao-Chung Cheng, Li Gao, Min-Hsiu Hsieh
Summary: This paper analyzes the fundamental properties of Renyi and Augustin information from a noncommutative measure-theoretic perspective, proving their uniform equicontinuity and concavity. It also provides applications in classical-quantum channel coding and classical data compression.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Xu-Fei Yin, Yuxuan Du, Yue-Yang Fei, Rui Zhang, Li-Zheng Liu, Yingqiu Mao, Tongliang Liu, Min-Hsiu Hsieh, Li Li, Nai-Le Liu, Dacheng Tao, Yu-Ao Chen, Jian-Wei Pan
Summary: This work presents an efficient quantum adversarial bipartite entanglement detection scheme, which can effectively identify entanglement states. By formulating the detection as a two-player zero-sum game completed by parameterized quantum circuits, the protocol is experimentally implemented on a linear optical network and shown to be effective in detecting 5-qubit quantum pure states and 2-qubit quantum mixed states.
PHYSICAL REVIEW LETTERS
(2022)
Article
Quantum Science & Technology
Yuxuan Du, Tao Huang, Shan You, Min-Hsiu Hsieh, Dacheng Tao
Summary: Variational quantum algorithms (VQAs) are a potential way to achieve quantum advantages on noisy quantum devices. However, the choice of quantum model greatly affects the algorithm's performance. To improve robustness and trainability, we propose a resource and runtime efficient scheme called quantum architecture search (QAS), which automatically seeks a near-optimal quantum model to balance benefits and side-effects.
NPJ QUANTUM INFORMATION
(2022)
Article
Computer Science, Information Systems
Yuxuan Du, Min-Hsiu Hsieh, Tongliang Liu, Shan You, Dacheng Tao
Summary: This paper introduces an efficient quantum differentially private (QDP) Lasso estimator for solving sparse regression tasks. The authors prove that the runtime cost of QDP Lasso is dimension independent and can be faster than both the optimal classical and quantum non-private Lasso. They also demonstrate that QDP Lasso achieves a near-optimal utility bound with privacy guarantees and discuss the potential for its implementation on near-term quantum chips with advantages.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Physics, Multidisciplinary
Margarite L. LaBorde, Mark M. Wilde
Summary: This study introduces quantum algorithms for testing symmetries in a Hamiltonian with respect to a specific group, demonstrating the algorithms' effectiveness through execution on existing quantum computers.
PHYSICAL REVIEW LETTERS
(2022)
Article
Computer Science, Information Systems
Jihao Fan, Jun Li, Ya Wang, Yonghui Li, Min-Hsiu Hsieh, Jiangfeng Du
Summary: In this paper, new families of quantum error correction codes achieving the quantum Gilbert-Varshamov (GV) bound asymptotically are constructed by utilizing a concatenation scheme. The Calderbank-Shor-Steane (CSS) codes are obtained by concatenating alternant codes with any linear code achieving the classical GV bound. It is shown that the concatenated code can achieve the quantum GV bound asymptotically and approach the Hashing bound for asymmetric Pauli channels. Furthermore, enlarged stabilizer codes achieving the quantum GV bound for enlarged CSS codes asymptotically are derived using Steane's enlargement construction of CSS codes.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Computer Science, Information Systems
Dawei Ding, Sumeet Khatri, Yihui Quek, Peter W. Shor, Xin Wang, Mark M. Wilde
Summary: This paper introduces various measures of forward classical communication for bipartite quantum channels. These measures reduce to measures of classical communication for point-to-point channels since a point-to-point channel is a special case of a bipartite channel. The reduced measures have been reported in prior work and used to bound the classical capacity of a quantum channel. As applications, the measures are shown to be upper bounds on the forward classical capacity of a bipartite channel and the classical capacity of a point-to-point quantum channel assisted by a classical feedback channel. Some of the measures can be computed using semi-definite programming.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2023)
Article
Quantum Science & Technology
Jun Qi, Chao-Han Huck Yang, Pin-Yu Chen, Min-Hsiu Hsieh
Summary: In this work, an end-to-end quantum neural network TTN-VQC is proposed, which combines a quantum tensor network based on tensor-train network (TTN) for dimensionality reduction and a VQC for functional regression. The error performance analysis is conducted to evaluate the representation and generalization powers of TTN-VQC, and the optimization properties are characterized using the Polyak-Lojasiewicz condition. Additionally, experiments on a handwritten digit classification dataset are conducted to validate the theoretical analysis.
NPJ QUANTUM INFORMATION
(2023)
Article
Optics
Ludovico Lami, Mark M. Wilde
Summary: This study provides an exact calculation method for the quantum, private, two-way assisted quantum, and secret-key-agreement capacities of all bosonic dephasing channels. The authors prove that these capacities are equal to the relative entropy of the distribution underlying the channel with respect to the uniform distribution.
Article
Multidisciplinary Sciences
Zachary P. P. Bradshaw, Margarite L. L. LaBorde, Mark M. M. Wilde
Summary: This paper investigates whether the mixedness of a pure bipartite state determines the separability and entanglement of the overall state. The researchers conduct quantum computational tests of mixedness and obtain an exact expression for the acceptance probability of such tests as the number of state copies increases. They demonstrate that the analytical form of this expression is given by the cycle index polynomial of the symmetric group S-k, which is related to Bell polynomials. Furthermore, they propose a family of quantum separability tests generated by finite groups, where the acceptance probability is determined by the cycle index polynomial of the group. Finally, they present and analyze explicit circuit constructions for these tests, demonstrating that the tests corresponding to symmetric and cyclic groups can be executed with O(k(2)) and O(klog(k)) controlled-SWAP gates, respectively, where k is the number of state copies being tested.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Quantum Science & Technology
Nic Ezzell, Elliott M. Ball, Aliza U. Siddiqui, Mark M. Wilde, Andrew T. Sornborger, Patrick J. Coles, Zoe Holmes
Summary: The task of learning a quantum circuit to prepare a given mixed state is addressed using a variational quantum algorithm (VQA) suitable for near-term hardware. Two different approaches are considered to compile the target state: learning a purification of the state and representing it as a convex combination of pure states. By learning a lower rank approximation of the target state, the algorithm offers a means of compressing a state for more efficient processing. The algorithm also effectively learns the principal components of the target state, providing a new method for principal component analysis.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Optics
Hemant K. Mishra, Samad Khabbazi Oskouei, Mark M. Wilde
Summary: In this paper, an analytical approach for determining optimal input states for continuous-variable (CV) unidirectional and bidirectional teleportation is detailed. The metric used to quantify performance is the energy-constrained channel fidelity between ideal and experimental teleportation. The paper proves that, under certain energy constraints, the optimal input state is a finite entangled superposition of twin-Fock states, and it is unique.
Article
Optics
Bartosz Regula, Ludovico Lami, Mark M. Wilde
Summary: The quantum relative entropy is no longer sufficient to describe the rates of asymptotic state transformations when stochastic protocols are allowed. A new entropic quantity based on a regularization of the Hilbert projective metric comes into play. This allows for constructing transformation protocols that achieve higher rates than those imposed by the relative entropy.
Article
Optics
Tharon Holdsworth, Vishal Singh, Mark M. Wilde
Summary: The ideal realization of quantum teleportation relies on having access to a maximally entangled state, but in practice, an ideal state is usually not available. Therefore, this study presents a method to quantify the performance of approximate teleportation using arbitrary resource states. By framing approximate teleportation as an optimization task and establishing a semidefinite relaxation, it is possible to evaluate the performance of various resource states and channels.
Article
Optics
Xin Wang, Mark M. Wilde
Summary: This paper establishes single-letter formulas for the exact entanglement cost of simulating quantum channels under free quantum operations that completely preserve positivity of the partial transpose (PPT). The kappa-entanglement measure for point-to-point quantum channels is introduced, along with several fundamental properties. The exact entanglement cost for simulating quantum channels in both the parallel and sequential settings is solved, and it is shown that the cost is equal to the kappa-entanglement measure of a quantum channel.
