Article
Materials Science, Multidisciplinary
Rafael A. Macedo, Flavia B. Ramos, Rodrigo G. Pereira
Summary: This study focuses on the problem of time-reversal symmetry breaking in quantum spin systems and presents a method to construct one-dimensional anisotropic spin models. It introduces the phenomenon of Landau-forbidden continuous phase transition and provides a concrete example. The results show that the transition between chiral and magnetic phases exhibits an emergent U(1) symmetry, with excitations resembling mobile defects binding fermionic modes.
News Item
Physics, Multidisciplinary
Simone Gasparinetti
Summary: The emission of light from qubits in a superconducting circuit can be controlled to determine the direction of photon propagation, allowing for information routing in quantum networks.
Article
Materials Science, Multidisciplinary
Anne E. B. Nielsen, Benedikt Herwerth, J. Ignacio Cirac, German Sierra
Summary: In this study, a class of tensor network states for spin systems were defined, with individual tensors being functionals of fields. Based on the path-integral representation of correlators in quantum field theory, these infinite-dimensional tensor network states were found to be related to matrix product states and projected entangled pair states. The field tensor generating the Haldane-Shastry wave function was identified and extended to two dimensions, providing evidence for its role in the topological chiral state described by the Kalmeyer-Laughlin wave function.
Article
Chemistry, Inorganic & Nuclear
Qing Li, Haonan Liu, Hongwei Yu, Zhanggui Hu, Jiyang Wang, Yicheng Wu, Hongping Wu
Summary: This research reports the fourth polymorph of KMoO3(IO3), i.e., delta-KMoO3(IO3), to investigate the influence of different packing patterns of basic building units on the structures and properties. The study shows that the polarization of delta-KMoO3(IO3) mainly comes from IO3 units. Further measurements reveal that delta-KMoO3(IO3) exhibits a large second-harmonic generation response, a wide band gap, and a broad mid-infrared transparency region, indicating the effective approach of adjusting the arrangement of ?-shaped basic building units in rational design of NLO crystals.
INORGANIC CHEMISTRY
(2023)
Article
Quantum Science & Technology
Yao Tang, Tao Shang, Jianwei Liu
Summary: This article proposes a universal construction method for a full quantum one-way function, addressing the threat of quantum computers to traditional one-way functions. The new full quantum one-way function can directly transform information between quantum systems and is more suitable for quantum cryptographic schemes. It is beneficial for the security of quantum message authentication.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Physics, Multidisciplinary
Xiao-Wei Wang, Wen-Hao Zhou, Yu-Xuan Fu, Jun Gao, Yong-Heng Lu, Yi-Jun Chang, Lu-Feng Qiao, Ruo-Jing Ren, Ze-Kun Jiang, Zhi-Qiang Jiao, Georgios M. Nikolopoulos, Xian-Min Jin
Summary: Through experiments, we demonstrate that the implementation of a cryptographic one-way function based on coarse-grained boson sampling in a photonic boson-sampling machine requires a moderate sample size, much smaller than predicted by the Chernoff bound. Nonboson samplers cannot generate the same output for numbers of photons n >= 3 and bins d similar to poly(m, n). Our study is the first experimental exploration of the potential applications of boson sampling in cryptography and paves the way for further research in this direction.
PHYSICAL REVIEW LETTERS
(2023)
Review
Biochemistry & Molecular Biology
Marco Antonio Chaer Nascimento
Summary: VB and MO models are distinguished by their treatment of molecules and the consideration of symmetry in the many-electron Hamiltonian. VB wave functions exhibit permutation symmetry, which is lacking in MO wave functions, leading to conflicts between practitioners. The concepts introduced by Pauling for dealing with molecules can also be applied to atomic structure, demonstrating the greater generality and versatility of the VB model.
Article
Multidisciplinary Sciences
Kai Yang, Soo-Hyon Phark, Yujeong Bae, Taner Esat, Philip Willke, Arzhang Ardavan, Andreas J. Heinrich, Christopher P. Lutz
Summary: Designing and characterizing many-body behaviors of quantum materials is crucial for understanding strongly correlated physics and quantum information processing. By constructing artificial quantum magnets with spin-1/2 atoms in a scanning tunneling microscope, researchers are able to study exotic quantum many-body states like the resonating valence bond state at an atomic scale. This approach offers a new avenue for designing and exploring quantum magnets for spintronics and quantum simulations.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Robert Trenyi, Marcos Curty
Summary: Coherent-one-way quantum key distribution (QKD) promises to distribute secret keys over long distances with a simple setup, but recent studies show that its secret key rate only scales at most quadratically with the system's transmittance, making it unsuitable for long distance transmission.
NEW JOURNAL OF PHYSICS
(2021)
Article
Quantum Science & Technology
Manish Kumar Mehta, Joseph Thomas Andrews, Pratima Sen
Summary: In this paper, a novel method is proposed to overcome the limitations of exciton and biexciton states only appearing at low temperatures, as well as the complexity of using lasers with different polarization states for CNOT operations. By utilizing ultrafast magnetic pulse CNOT gate operation in Mn-doped InSb quantum dots at room temperature, with only a circularly polarized laser pulse, the proposed method shows a significantly large fidelity calculation for CNOT gate.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Chemistry, Physical
Xiao-Han Zhang, Bing-Ping Yang, Chun-Li Hu, Jin Chen, Qian-Ming Huang, Jiang-Gao Mao
Summary: The anhydrous rare-earth metal iodate fluoride Ce(IO3)(2)F-2 features a unique three-dimensional structure with excellent optical properties, making it a potential nonlinear optical material superior to the hydrous counterpart Ce(IO3)(2)F-2(H2O).
CHEMISTRY OF MATERIALS
(2021)
Article
Quantum Science & Technology
Ljubomir Budinski
Summary: A novel quantum algorithm for solving advection-diffusion equation by the lattice Boltzmann method is proposed, which combines equilibrium distribution functions and quantum walk procedure. The algorithm's validity is demonstrated using the Qiskit framework and future research directions are discussed.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Physics, Multidisciplinary
Yixuan Huang, D. N. Sheng
Summary: In this study, the quantum phase diagram of unconventional topological superconductivity (TSC) on a triangular lattice was investigated using state-of-the-art density matrix renormalization group simulations. Different superconducting phases with nonzero topological Chern numbers and a nematic d-wave superconducting phase with a zero Chern number were identified. TSC states were found to emerge from doping a magnetic insulator or chiral spin liquid, opening new opportunities for experimental discovery.
Article
Quantum Science & Technology
Yao Tang, Tao Shang, Jianwei Liu
Summary: A dynamic full quantum one-way function based on quantum circuit mapping is proposed, which achieves the dynamic process of mapping quantum states by optimizing quantum circuits. The function shows better realizability and is proven to be significant in quantum cryptography.
QUANTUM INFORMATION PROCESSING
(2023)
Article
Chemistry, Multidisciplinary
Qi-Ming Qiu, Ke-Ning Sun, Guo-Yu Yang
Summary: By altering the metal salt used, different rubidium borates with unique chain structures or oxoboron layers can be synthesized. Compound 4 exhibits a high SHG response, demonstrating good nonlinear optical properties compared to related analogues.
Article
Multidisciplinary Sciences
J. Pablo Bonilla Ataides, David K. Tuckett, Stephen D. Bartlett, Steven T. Flammia, Benjamin J. Brown
Summary: Research shows that using the XZZX code for fault-tolerant quantum computation offers remarkable performance and can surpass the hashing bound in experimentally relevant noise parameters. In cases where qubit dephasing is the dominant noise, this code has a practical decoder and exceeds previous thresholds. The code demonstrates favorable sub-threshold resource scaling and maintains advantages when performing fault-tolerant quantum computation, showing better performance and requiring fewer resources compared to the surface code.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Applied
T. J. Evans, W. Huang, J. Yoneda, R. Harper, T. Tanttu, K. W. Chan, F. E. Hudson, K. M. Itoh, A. Saraiva, C. H. Yang, A. S. Dzurak, S. D. Bartlett
Summary: Benchmarking and characterizing quantum states and logic gates are crucial in the development of quantum computing devices. This paper introduces a Bayesian approach called fast Bayesian tomography (FBT) for self-consistent process tomography and demonstrates its performance in characterizing a two-qubit gate set on a silicon-based spin qubit device.
PHYSICAL REVIEW APPLIED
(2022)
Article
Multidisciplinary Sciences
Lawrence Z. Cohen, Isaac H. Kim, Stephen D. Bartlett, Benjamin J. Brown
Summary: This paper presents a low-overhead fault-tolerant quantum computing scheme based on quantum low-density parity-check (LDPC) codes, which enables many logical qubits to be encoded using a modest number of physical qubits through long-range interactions. In this approach, logic gates operate through logical Pauli measurements, preserving both the protection of LDPC codes and low overheads in terms of required additional qubits. Compared to surface codes with the same code distance, there are estimated order-of-magnitude improvements in overheads for processing about 100 logical qubits using this approach. Given the high thresholds demonstrated by LDPC codes, it is suggested that fault-tolerant quantum computation at this scale may be achievable with a few thousand physical qubits at comparable error rates to current approaches.
Article
Multidisciplinary Sciences
C. G. L. Bottcher, S. P. Harvey, S. Fallahi, G. C. Gardner, M. J. Manfra, U. Vool, S. D. Bartlett, A. Yacoby
Summary: This study demonstrates a controllable spin-photon coupling based on a longitudinal interaction, enabling remote entangling operations in a quantum computer. By driving a singlet-triplet qubit near the resonator frequency, a longitudinal coupling with a high-impedance superconducting resonator is achieved. The energy splitting of the qubit is measured as a function of the drive amplitude and frequency, showing pronounced effects near the resonator frequency due to longitudinal coupling.
NATURE COMMUNICATIONS
(2022)
Editorial Material
Chemistry, Physical
Andre Saraiva, Stephen D. Bartlett
Summary: By encoding information redundantly in a three-spin-qubit silicon device and using a novel quantum gate, common errors can be protected against.
Article
Physics, Multidisciplinary
Markus Frembs, Sam Roberts, Earl T. Campbell, Stephen D. Bartlett
Summary: For certain computational tasks, quantum mechanics has a proven advantage over classical implementation. This study focuses on measurement-based quantum computation (MBQC) and refines its resource requirements in terms of allowed operations and the number of accessible qubits. By exploring non-adaptive MBQC and subtheories like stabilizer MBQC, the computational power and minimum qubit requirements for computing Boolean functions are determined. The results provide a more detailed characterization of the power of MBQC beyond contextuality.
NEW JOURNAL OF PHYSICS
(2023)
Article
Quantum Science & Technology
Rainer Kaltenbaek, Markus Arndt, Markus Aspelmeyer, Peter F. Barker, Angelo Bassi, James Bateman, Alessio Belenchia, Joel Berge, Claus Braxmaier, Sougato Bose, Bruno Christophe, Garrett D. Cole, Catalina Curceanu, Animesh Datta, Maxime Debiossac, Uros Delic, Lajos Diosi, Andrew A. Geraci, Stefan Gerlich, Christine Guerlin, Gerald Hechenblaikner, Antoine Heidmann, Sven Herrmann, Klaus Hornberger, Ulrich Johann, Nikolai Kiesel, Claus Laemmerzahl, Thomas W. LeBrun, Gerard J. Milburn, James Millen, Makan Mohageg, David C. Moore, Gavin W. Morley, Stefan Nimmrichter, Lukas Novotny, Daniel K. L. Oi, Mauro Paternostro, C. Jess Riedel, Manuel Rodrigues, Loic Rondin, Albert Roura, Wolfgang P. Schleich, Thilo Schuldt, Benjamin A. Stickler, Hendrik Ulbricht, Christian Vogt, Lisa Woerner
Summary: The objective of MACRO mission is to conduct macroscopic quantum experiments in space to test the foundations of physics at the interface with gravity. Developing necessary technologies and achieving required sensitivities for macroscopic quantum systems in extreme conditions is crucial. Recent scientific advancements promise potential for accomplishing additional science objectives and drive the research campaign.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Applied
Samuel C. Smith, Benjamin J. Brown, Stephen D. Bartlett
Summary: A fault-tolerant quantum computer requires a classical decoding system to interface with quantum hardware for quantum error correction. In order to keep up with the quantum clock speed and communication limitations imposed by the physical architecture, a local predecoder is proposed to make greedy corrections and reduce the amount of syndrome data sent to a standard matching decoder. This approach significantly improves the run time of the global decoder and the communication bandwidth.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Multidisciplinary
Mark A. Webster, Armanda O. Quintavalle, Stephen D. Bartlett
Summary: Storing quantum information in CSS codes and protecting it from errors is important, but being able to transform the information fault-tolerantly is equally significant. This research focuses on the study of transversal logical operators composed of diagonal Clifford hierarchy gates, aiming to identify them more generally and with lower computational complexity than previous methods. The research also presents a method for constructing CSS codes with a desired diagonal logical Clifford hierarchy operator. The techniques used in this work, such as representing operators as diagonal XP operators, may have broader applications.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Aditya Jain, Pavithran Iyer, Stephen D. Bartlett, Joseph Emerson
Summary: Current hardware for quantum computing suffers from high levels of noise, requiring efficient methods to correct for errors. This study explores the effectiveness of noise tailoring techniques, specifically randomized compiling, on improving error correcting codes' performance. The research shows that randomized compiling significantly improves the performance of the concatenated Steane code, particularly for coherent errors caused by control errors. It also suggests that increasing the size of the codes magnifies the gains in logical fidelity below a certain threshold rotation angle. These findings indicate that using randomized compiling can reduce the resource overhead for achieving fault tolerance.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Physics, Multidisciplinary
Pavithran Iyer, Aditya Jain, Stephen D. Bartlett, Joseph Emerson
Summary: This article presents a scalable experimental approach based on Pauli error reconstruction to predict the performance of concatenated codes. The method significantly outperforms predictions based on standard error metrics for various error models, even with limited data. It also assists in the selection of error correction schemes.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Quantum Science & Technology
Mark A. Webster, Benjamin J. Brown, Stephen D. Bartlett
Summary: We propose an extension to the Pauli stabiliser formalism, called the XP stabiliser formalism, which allows for a wider range of states and codespaces to be represented. We demonstrate an equivalence between XP stabiliser states and 'weighted hypergraph states' and present algorithms for determining the codespace and logical operators for an XP code. Finally, we consider whether measurements of XP operators on XP codes can be classically simulated.
Article
Quantum Science & Technology
Hakop Pashayan, Oliver Reardon-Smith, Kamil Korzekwa, Stephen D. Bartlett
Summary: Researchers present two classical algorithms for simulating universal quantum circuits, with each algorithm performing best in different parameter regimes. The ESTIMATE algorithm provides an estimate of measurement outcome probabilities with a specific precision, while the COMPUTE algorithm calculates probabilities to machine precision.
Article
Optics
Cooper Doyle, Wei-Wei Zhang, Michelle Wang, Bryn A. Bell, Stephen D. Bartlett, Andrea Blanco-Redondo
Summary: In this study, we achieved entanglement between different topological spatial modes in a bipartite array of silicon waveguides, demonstrating topology as an additional degree of freedom for entanglement and opening new avenues for investigating information teleportation.
Article
Physics, Multidisciplinary
Paul Webster, Michael Vasmer, Thomas R. Scruby, Stephen D. Bartlett
Summary: This paper presents a universal and fault-tolerant framework for quantum logic gates and reveals the broad conditions constraining such gate sets. It demonstrates how nonunitary implementations of logic gates can circumvent these constraints and provides a variety of constructions for universal and fault-tolerant logic gate sets.
PHYSICAL REVIEW RESEARCH
(2022)