Article
Physics, Multidisciplinary
Cheng Sheng, Jiayi Hou, Xiaodong He, Kunpeng Wang, Ruijun Guo, Jun Zhuang, Bahtiyar Mamat, Peng Xu, Min Liu, Jin Wang, Mingsheng Zhan
Summary: This study reports the first demonstration of two-dimensional dual-species atom assembly, achieved by rearranging initially randomly distributed atoms using a sorting algorithm and optical trapping technique. The resulting atom arrays have user-defined geometries and specific species ratios, making them highly attractive for applications in high-fidelity quantum logic, many-body quantum simulation, and single molecule array formation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Stephen D. Erickson, Jenny J. Wu, Pan-Yu Hou, Daniel C. Cole, Shawn Geller, Alex Kwiatkowski, Scott Glancy, Emanuel Knill, Daniel H. Slichter, Andrew C. Wilson, Dietrich Leibfried
Summary: This study proposes and demonstrates a protocol for high-fidelity indirect readout of trapped ion hyperfine qubits. By mapping the state of one ion to a readout ion using laser-driven Raman transitions, the protocol reduces errors and allows for repetition to improve readout fidelity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Quantum Science & Technology
Dong-Xu Chen, Junliang Jia, Pei Zhang, Chui-Ping Yang
Summary: This study presents two optimized architectures for effectively realizing arbitrary unitary transformations using photonic path and polarization. These architectures have significant importance in reducing the number of interferometers and transforming elementary operations.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Andrei Tanasescu, David Constantinescu, Pantelimon George Popescu
Summary: The author proposed a distributed quantum computation protocol for small register devices, enabling the distribution of controlled unitary gates and leveraging quantum sharing of partial results for parallel processing, achieving for the first time the quantum distribution of very large gates using small register devices.
SCIENTIFIC REPORTS
(2022)
Review
Quantum Science & Technology
Huaijin Zhang, Xingyan Chen, Zhang-qi Yin
Summary: This article introduces the levitation of nanodiamonds and the basic physics of nitrogen-vacancy centers, explores methods for quantum information processing and precision measurement using these properties, and discusses applications in areas such as mass spectrometry and gravitational acceleration measurement.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Article
Optics
Fernando Martinez-Garcia, Lukas Gerster, Davide Vodola, Pavel Hrmo, Thomas Monz, Philipp Schindler, Markus Mueller
Summary: Studied the impact of calibration errors on the gate performance in the Mt lmer-St rensen entangling gate and verified the predictions through experiments.
Article
Optics
K. Sosnova, A. Carter, C. Monroe
Summary: For high-fidelity entangling gates based on transverse modes for mixed-species ion chains with large mass ratio, the laser power required is at least an order of magnitude higher than that for gates based on axial modes. Additionally, even with moderate mass differences, the transverse modes are much harder to cool than the axial modes.
Article
Computer Science, Hardware & Architecture
Nadia Nedjah, Sergio Raposo, Luiza de Macedo Mourelle
Summary: This work presents a novel approach to quantum computing by proposing a customizable hardware design of a dedicated processor that emulates the execution of quantum algorithms. The proposed hardware design overcomes the limitations of software-based simulators by utilizing parallelism and pipelined execution, delivering improved performance for emulating quantum algorithms. The architecture includes key components such as memories, computation unit, measurement unit, and control unit, which work together to efficiently execute quantum operations.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Computer Science, Information Systems
Michal Oszmaniec, Adam Sawicki, Michal Horodecki
Summary: In this work, quantitative connections between epsilon-nets and approximate unitary t-designs are studied, revealing their relationship in d-dimensional Hilbert space and their applications in quantum computing. The results show near optimality and the potential for new construction methods in quantum computing.
IEEE TRANSACTIONS ON INFORMATION THEORY
(2022)
Article
Optics
Hao Song, Kaiheng Zou, Huibin Zhou, Narek Karapetyan, Amir Minoofar, Xinzhou Su, Ahmed Almaiman, Jonathan L. Habif, Moshe Tur, Alan E. Willner
Summary: This paper experimentally demonstrates an optics-based half-adder for two 4-phase-shift-keying (4-PSK) data channels using nonlinear wave mixing. The half-adder has high conversion efficiency and low optical signal-to-noise ratio (OSNR).
Article
Optics
Anupam Mitra, Sivaprasad Omanakuttan, Michael J. Martin, Grant W. Biedermann, Ivan H. Deutsch
Summary: This paper revisits the implementation of a two-qubit entangling gate called Mt lmer-St rensen gate using adiabatic Rydberg dressing for neutral atoms. The study shows that rapid adiabatic passage can be achieved through a two-photon transition without the need for an ultraviolet laser, by simply modulating the amplitude of one field with fixed laser frequencies. The results demonstrate that entangling gate fidelities comparable to the one-photon excitation can be achieved with the two-photon excitation. Furthermore, the paper explores how the adiabatic dressing protocol can be used to implement entangling gates beyond the regime of a perfect Rydberg blockade, allowing for fast high-fidelity gates for atoms separated beyond the blockade radius.
Article
Optics
Dong-Xu Chen, Yunlong Wang, Feiran Wang, Jun-Long Zhao, Chui-Ping Yang
Summary: High-dimensional quantum systems have advantages over low-dimensional ones, but unitary transformations on quantum states become technically infeasible as the dimensionality increases. Photonic orbital angular momentum (OAM) provides a natural carrier to encode information in high-dimensional spaces. This work proposes an efficient scheme to realize arbitrary unitary transformations on the path-OAM coupled quantum states by combining the path and OAM degrees of freedom of a single photon. It reduces the number of required interferometers while maintaining the symmetric structure, and can be used to manipulate the photonic OAM states.
LASER & PHOTONICS REVIEWS
(2023)
Article
Physics, Multidisciplinary
Gui-Long Jiang, Hai-Rui Wei, Guo-Zhu Song, Ming Hua
Summary: The authors propose a quantum circuit model for implementing complex quantum computation. They show that certain gates and rotations can simulate controlled-unitary gates and diagonal unitary gates. The quantum circuits for implementing the target gates are also presented.
ANNALEN DER PHYSIK
(2022)
Article
Engineering, Electrical & Electronic
Francesco Maria Puglisi, Tommaso Zanotti, Paolo Pavan
Summary: This paper proposes a new synthesis method for implication logic circuits based on memristors by revisiting Boole's expansion theorem. The method optimizes the operation sequence and reduces the number of memristors, while leveraging well-established logic circuit optimization methods. It outperforms existing approaches and allows for a fair comparison between CMOS and implication logic implementations under the same level of optimization, with possible device-circuit co-design strategies discussed for optimizing circuit performance.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2021)
Article
Automation & Control Systems
Sheh-Yi Sheu, Hua-Yi Hsu, Dah-Yen Yang
Summary: DNA, RNA, and protein are demonstrated as promising media for QCs, using residue pairs for quantum logic gates via proton-coupled electron transfer. Transfer of protons between donor and acceptor states fulfill qubits, with specific pairs obeying Toffoli, SWAP, and CNOT gates, while amino acids achieve 1-qubit and satisfy Pauli-X, -Y, and -Z gates. Universal quantum logic gate generators are obtained.
ADVANCED INTELLIGENT SYSTEMS
(2021)
Article
Optics
Leili Esmaeilifar, Timothy C. Ralph
Summary: The use of a nonlinear optical interferometer for estimating local gravitational acceleration is investigated. A Mach-Zehnder interferometer (MZI) in an optical fountain configuration with a Kerr nonlinear medium in the arms is studied. This configuration allows parameter estimation beyond the standard Heisenberg limit of a linear interferometer. Compared to previous studies, it is argued that this interferometer configuration is better posed and achieves improved precision for similar scale and pump powers.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Joshua J. Guanzon, Matthew S. Winnel, Austin P. Lund, Timothy C. Ralph
Summary: We introduce a linear optical technique that can achieve ideal quantum teleamplification, improving success probability and resource efficiency. We also demonstrate its applications as a loss-tolerant quantum relay for entanglement distribution and distillation.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Sergei Slussarenko, Morgan M. Weston, Lynden K. Shalm, Varun B. Verma, Sae-Woo Nam, Sacha Kocsis, Timothy C. Ralph, Geoff J. Pryde
Summary: This study demonstrates successful channel correction for long-distance quantum communication, improving the transmission performance of entangled channels without relying on post-processing or post-selection of data.
NATURE COMMUNICATIONS
(2022)
Article
Astronomy & Astrophysics
Lachlan G. Bishop, Timothy C. Ralph, Fabio Costa
Summary: Past studies on the billiard-ball paradox have focused on classical histories, while this study develops a quantum version using a quantum circuit to describe various paths. The model finds self-consistent solutions using Deutsch's prescription and pure-state solutions using the postselected teleportation prescription. The study also discusses methods for ensuring convergence in the continuum limit.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Physics, Multidisciplinary
James Q. Quach, Timothy C. Ralph, William J. Munro
Summary: This study explores the geometric phase resulting from timelike entanglement between future and past, showing that it can be captured in a simple A system. It provides an alternative paradigm to the Unruh-deWitt detector.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Lorcan O. Conlon, Tobias Vogl, Christian D. Marciniak, Ivan Pogorelov, Simon K. Yung, Falk Eilenberger, Dominic W. Berry, Fabiana S. Santana, Rainer Blatt, Thomas Monz, Ping Koy Lam, Syed M. Assad
Summary: Entanglement, a fundamental feature of quantum mechanics, shows great potential for enhancing metrology and communications. Current focus in quantum metrology has been on generating highly entangled states for improved sensitivity. However, to achieve ultimate limits in multi-parameter quantum metrology and information processing, collective measurements that generate entanglement between multiple copies of quantum states are necessary. Optimal single and two-copy collective measurements for estimating non-commuting qubit rotations have been experimentally demonstrated, enabling quantum-enhanced sensing even under high decoherence levels and providing insights into the uncertainty principle. Superconducting, trapped-ion, and photonic systems were used to implement these optimal measurements, giving a glimpse into future quantum-enhanced sensing networks.
Article
Quantum Science & Technology
Matthew S. Winnel, Joshua J. Guanzon, Nedasadat Hosseinidehaj, Timothy C. Ralph
Summary: This study proposes a practical design for achieving the ultimate end-to-end rates of quantum communication networks through an iterative approach and entanglement distillation protocol. An experimental implementation using linear optics and photon-number measurements is also proposed.
NPJ QUANTUM INFORMATION
(2022)
Article
Quantum Science & Technology
Ozlem Erkilic, Lorcan Conlon, Biveen Shajilal, Sebastian Kish, Spyros Tserkis, Yong-Su Kim, Ping Koy Lam, Syed M. M. Assad
Summary: Decoherence is a problem for quantum key distribution (QKD) over long distances. This paper proposes the use of quantum repeaters to minimize the effects of losses in the channel by dividing the total distance between users into smaller segments. A measurement-device-independent protocol is introduced, which uses high-dimensional states prepared by two trusted parties and a coherent total photon number detection for entanglement swapping at the repeater station. The experimentally feasible protocol achieves better key rates and longer transmission distance compared to existing protocols, surpassing the fundamental limit of repeaterless bound even at a shorter distance than existing TF-QKD protocols.
NPJ QUANTUM INFORMATION
(2023)
Article
Physics, Multidisciplinary
Lorcan O. Conlon, Ping Koy Lam, Syed M. Assad
Summary: This study compares the performance of single- and two-qubit probes for estimating multiple phase rotations under different noisy channels, showing that two-qubit probes exhibit enhanced parameter estimation capabilities. Entanglement is required in both the state preparation and state measurement stages to reach the ultimate precision limits allowed by quantum mechanics.
Article
Multidisciplinary Sciences
Jie Zhao, Hao Jeng, Lorcan O. Conlon, Spyros Tserkis, Biveen Shajilal, Kui Liu, Timothy C. Ralph, Syed M. Assad, Ping Koy Lam
Summary: This article presents a protocol that uses heralded noiseless amplification to increase the fidelity of continuous-variable quantum teleportation. The method allows for high-fidelity teleportation of coherent states and purification of thermalized input states, overcoming long-standing hurdles in continuous-variable quantum teleportation. These results have both practical and fundamental significance.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Bohan Li, Aritra Das, Spyros Tserkis, Prineha Narang, Ping Koy Lam, Syed M. Assad
Summary: The maximum entanglement achievable through passive transformations by continuous-variable states is called the entanglement potential. Recent research indicates that the entanglement potential can be upper-bounded by a simple function of squeezing of formation. Certain classes of two-mode Gaussian states can saturate this bound, but it remains an open problem for the general case. In this study, a larger class of states is introduced that is proven to saturate the bound, and it is conjectured that all two-mode Gaussian states can be passively transformed into this class, thereby equating entanglement potential with squeezing of formation. An explicit algorithm for the passive transformations is provided, and extensive numerical testing is performed to support this claim, aiming to unify the resource theories of two characteristic quantum properties of continuous-variable systems.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Wanli Xing, T. C. Ralph
Summary: We have derived analytical solutions for the Heisenberg evolution under the trilinear parametric Hamiltonian, which are accurate up to second order in the interaction strength and valid for all pump amplitudes. These solutions enable the incorporation of pump depletion effects in the description of optical parametric amplification in experimentally relevant scenarios and provide a rigorous description of the resulting phenomena.
Article
Astronomy & Astrophysics
Sho Onoe, Thiago L. M. Guedes, Andrey S. Moskalenko, Alfred Leitenstorfer, Guido Burkard, Timothy C. Ralph
Summary: A new theoretical framework is proposed to describe the experimental advances in electro-optic detection of broadband quantum states. By utilizing concepts from quantum field theory, the nonlinear interaction behind the electro-optic effect is shown to be equivalent to a Unruh-DeWitt detector coupled to a conjugate field. The analysis accurately captures the quantum nature of the vacuum and proposes a specific working regime to experimentally verify the existence of virtual photons with quantum correlations in the electromagnetic ground state.
Article
Optics
Joshua Foo, Sho Onoe, Magdalena Zych, Timothy C. Ralph
Summary: This article presents theoretical models for quantum-optical mode-selective filters and mirrors using continuous-variable teleportation. These devices, known as telefilters and telemirrors, can act as identity channels for specific modes while filtering or reflecting all other modes. The models are used to analyze causality problems in relativistic quantum optics, particularly the transmission and propagation of delocalized wave packets through mode-selective mirrors. The research demonstrates the importance of time delay and considers the discrimination and selection of different modes.
Article
Optics
Nedasadat Hosseinidehaj, Matthew S. Winnel, Timothy C. Ralph
Summary: The continuous-variable quantum key distribution protocol discussed in the text utilizes a bright laser for modulation and self-homodyne detection, resulting in a simpler and more robust approach compared to traditional methods. By properly modulating the squeezed laser and making certain assumptions, the protocol can eliminate information leakage to eavesdroppers and increase tolerance to loss.
