Article
Physics, Multidisciplinary
Michal P. Heller, Alexandre Serantes, Micha Spalinski, Benjamin Withers
Summary: We use causality to derive constraints on dispersion relations, which describe the location of singularities of retarded two-point functions in relativistic quantum field theories. We prove that all causal dissipative dispersion relations have a finite radius of convergence when stochastic fluctuations are negligible. Then, we provide two-sided bounds on all transport coefficients, including an upper bound on diffusivity, in units of this radius.
PHYSICAL REVIEW LETTERS
(2023)
Article
Computer Science, Artificial Intelligence
Birgit Hillebrecht, Benjamin Unger
Summary: The article presents a rigorous upper bound on the prediction error of physics-informed neural networks (PINNs). This bound can be calculated without knowing the true solution and only requires prior knowledge about the characteristics of the underlying dynamical system. The authors exemplify the application of this posteriori error bound to four different problems.
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS
(2023)
Article
Physics, Multidisciplinary
Andrea Guerrieri, Amit Sever
Summary: This study presents a dual S-matrix bootstrap approach in dimensions greater than or equal to three, relying on the rigorously proven properties of scattering amplitudes. The approach provides numerical bounds for identical scalar particle scattering in four dimensions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Jiaan Qi, Xiansong Xu, Dario Poletti, Hui Khoon Ng
Summary: Dynamical decoupling (DD) is a widely used error mitigation method that aims to eliminate slowly evolving noise in quantum systems using pulse sequences. However, in the presence of noisy pulses, DD does not always effectively mitigate errors. It only works when the noise introduced by imperfect DD pulses is not greater than the original background noise.
Article
Astronomy & Astrophysics
Valentin Kasper, Torsten V. Zache, Fred Jendrzejewski, Maciej Lewenstein, Erez Zohar
Summary: Lattice gauge theories play a fundamental role in various fields such as particle physics, condensed matter, and quantum information theory. While recent advancements in controlling artificial quantum systems have allowed for studying Abelian lattice gauge theories in tabletop experiments, realizing non-Abelian models remains challenging. In this study, we propose a coherent quantum control scheme to enforce non-Abelian gauge invariance in a one-dimensional SU(2) lattice gauge system and discuss the potential extension to other non-Abelian gauge symmetries and higher spatial dimensions. The presented coherent control scheme holds promise for the quantum simulation of non-Abelian lattice gauge theories due to its wide applicability.
Article
Physics, Fluids & Plasmas
Liming Pan, Wei Wang, Lixin Tian, Ying-Cheng Lai
Summary: Studying the optimal network structure for the susceptible-infected-susceptible type of dynamics on annealed networks reveals that the optimal degree distribution varies for different infection rates in terms of quantity and support range. Additionally, the heterogeneity of the optimal networks decreases with the infection rate.
Article
Mathematics, Applied
Robert J. Webber, Erik H. Thiede, Douglas Dow, Aaron R. Dinner, Jonathan Weare
Summary: In this paper, the error of a dynamical spectral estimation method called VAC is analyzed by bounding the approximation error and estimation error. The analysis establishes the convergence properties of VAC and suggests new strategies for tuning VAC to improve accuracy.
SIAM JOURNAL ON MATHEMATICS OF DATA SCIENCE
(2021)
Article
Automation & Control Systems
Michiel Burgelman, Paolo Forni, Alain Sarlette
Summary: This manuscript investigates the strategy of decoupling a target system from a noisy environment subsystem by acting on the environment. The study considers two versions of environment-side decoupling and concludes that isolating the environment from noise sources may not always be the best option. The induced decoherence on the target system is analyzed, and the parameters' influence on induced decoherence is established.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2023)
Article
Physics, Multidisciplinary
Benjamin Merkel, Pablo Cova Farina, Andreas Reiserer
Summary: Ensembles of dopants have wide applications in quantum technology, but the miniaturization of corresponding devices is hindered by dipolar interactions. Dynamical decoupling can alleviate the decoherence in crystals with strong anisotropic spin-spin interactions, originating from anisotropic g tensor, but cannot fully eliminate it. These findings can be extended to various quantum systems used for quantum sensing, microwave-to-optical conversion, and quantum memory.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Miao Cai, Keyu Xia
Summary: In this study, we use a black-box optimization process in a machine learning algorithm to optimize the continuous dynamical decoupling scheme and improve the coherence of a quantum state. By applying a discrete optimization process to continuous driving fields, we achieve a longer coherence time compared to representative schemes of dynamical decoupling. Our black-box optimization-based machine learning algorithm provides a general routine to address the challenging task of improving the coherence of a quantum state, in which the dephasing of the system is crucial for operation.
Article
Optics
Xinxing Yuan, Yue Li, Mengxiang Zhang, Chang Liu, Mingdong Zhu, Xi Qin, Nikolay V. Vitanov, Yiheng Lin, Jiangfeng Du
Summary: A proof-of-principle experiment demonstrates the use of dynamical decoupling to protect superpositions in multilevel systems (qudits) from environmental magnetic field interference, significantly prolonging coherence. This experiment opens up possibilities for long coherence quantum memory, metrology, and information processing with qudits.
Article
Optics
P. Z. Zhao, X. Wu, D. M. Tong
Summary: This paper presents a method combining nonadiabatic holonomic quantum computation and dynamical decoupling to protect quantum gates from control errors and environment-induced decoherence. The protocol achieves robustness against both types of errors.
Article
Physics, Multidisciplinary
Patrick Barthel, Patrick H. Huber, Jorge Casanova, Inigo Arrazola, Dorna Niroomand, Theeraphot Sriarunothai, Martin B. Plenio, Christof Wunderlich
Summary: We demonstrate the experimental implementation of a two-qubit phase gate using a radio frequency controlled trapped-ion quantum processor. The gate is generated by applying a pulsed dynamical decoupling sequence to the ions' carrier transitions, allowing for tunable and high-fidelity phase shift. The gate's performance is robust against various sources of error and holds potential for fast gate speeds.
NEW JOURNAL OF PHYSICS
(2023)
Article
Mathematics, Applied
Patrick Wright, Jitse Niesen, Rob Sturman
Summary: Rigorous, elementary upper and lower bounds on the Lyapunov exponents of a parametrised family of linked twist maps are explicitly obtained for a specific range of parameter values. The method used relies on the existence of invariant cones for specific products of the shear maps and the partitioning of the overlap region of the two annuli based on return time. The accuracy of this method is improved by considering preceding sequences of matrices on the orbits.
Article
Quantum Science & Technology
Alexandre M. Souza
Summary: In this study, dynamical decoupling sequences were tested on a single qubit using the Rigetti quantum computing platform. It was found that pulse imperfections limited the performance, but using robust sequences improved the effectiveness of dynamical decoupling. The tested sequences outperformed previous ones on the same platform.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Quantum Science & Technology
Mostafa Khezri, Jeffrey A. Grover, James I. Basham, Steven M. Disseler, Huo Chen, Sergey Novikov, Kenneth M. Zick, Daniel A. Lidar
Summary: The study focused on a high coherence four-junction capacitively shunted flux qubit (CSFQ) and implemented a nonlinear annealing path to correct Josephson junction asymmetry, leading to an increased probability of the qubit being in the correct state. By annealing through small spectral gaps, the multi-level structure of the CSFQ circuit model was confirmed.
NPJ QUANTUM INFORMATION
(2021)
Article
Quantum Science & Technology
Matthew Kowalsky, Tameem Albash, Itay Hen, Daniel A. Lidar
Summary: With the saturation of current semiconductor technology, special-purpose hardware has become an alternative solution for specific computation-intensive challenges. This research attempts to assess and compare the performance of different dedicated optimization hardware approaches using a mapping of linear equations, providing insights into their promise and limitations for a particular class of optimization problems.
QUANTUM SCIENCE AND TECHNOLOGY
(2022)
Article
Physics, Applied
Mostafa Khezri, Xi Dai, Rui Yang, Tameem Albash, Adrian Lupascu, Daniel A. Lidar
Summary: This article introduces how to use superconducting circuits to construct quantum annealing systems, and control the annealing schedule during the annealing process to improve the success probability of the annealing protocol.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Yuki Bando, Ka-Wa Yip, Huo Chen, Daniel A. Lidar, Hidetoshi Nishimori
Summary: This paper reports the results of reverse annealing experiments using the D-Wave 2000Q device. The study focuses on the p = 2 p-spin problem and observes a strong asymmetry in the partial success probabilities. By performing open-system simulations, it is found that the adiabatic master equation fails to agree with the experiment, while the polaron transformed Redfield equation is in close agreement.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
Haimeng Zhang, Bibek Pokharel, E. M. Levenson-Falk, Daniel Lidar
Summary: This study utilizes a simple model called the post-Markovian master equation to accurately capture and predict non-Markovian noise in a superconducting qubit system. The model also allows for the extraction of information about crosstalk and measures of non-Markovianity.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Huo Chen, Daniel A. Lidar
Summary: This article introduces an open-source software package called Hamiltonian Open Quantum System Toolkit (HOQST) for simulating the dynamics of open quantum systems in Hamiltonian quantum computing. It features key master equations suitable for describing the dynamics of a reduced system coupled to a quantum bath with an arbitrary time-dependent Hamiltonian.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Applied
Vinay Tripathi, Huo Chen, Mostafa Khezri, Ka-Wa Yip, E. M. Levenson-Falk, Daniel A. Lidar
Summary: The current available superconducting quantum processors are noisy and prone to errors, which can be suppressed by using dynamical decoupling to suppress crosstalk. We demonstrated the success of this scheme through experiments on several IBM quantum cloud processors and achieved improvements in quantum memory and gate operations. Our work paves the way for higher-fidelity logic gates in transmon-based quantum computers.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Multidisciplinary
Gary Schmiedinghoff, Leanna Mueller, Umesh Kumar, Goetz S. Uhrig, Benedikt Fauseweh
Summary: This study provides theoretical and numerical evidence for the existence of stable three-particle bound states induced by irreducible three-particle interactions in antiferromagnetic spin ladders. The findings have important implications for understanding the dynamics of quantum many-particle states and for experimental detection.
COMMUNICATIONS PHYSICS
(2022)
Article
Multidisciplinary Sciences
Evgeny Mozgunov, Daniel A. Lidar
Summary: We propose a new quantum adiabatic theorem to bound the adiabatic timescale for various systems, including those with originally unbounded Hamiltonian. Our bound is specifically effective for qubits in superconducting circuits and does not contain a factor of 2n in the timescale, unlike previous results. We also demonstrate the dependence of the timescale on circuit parameters and discuss a method for obtaining an effective Hamiltonian approximating the true dynamics induced by slowly changing control parameters.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Physics, Multidisciplinary
Gary Schmiedinghoff, Goetz S. Uhrig
Summary: Open quantum systems and their interactions with the environment are crucial for the development of novel quantum technologies. In this study, the authors generalize the particle conserving generator to non-Hermitian matrices and open quantum systems governed by Lindbladians. The advocated generator demonstrates efficient and accurate flow, outperforming the recently proposed generators by Rosso et al.
Article
Materials Science, Multidisciplinary
Philip Bleicker, Dag-Bjoern Hering, Gotz S. Uhrig
Summary: Using both a semianalytical and a numerically exact method, this study investigates the charge dynamics near half-filling in the one- and two-dimensional t-J model derived from the Fermi-Hubbard model. The results suggest that band edges may not exist when magnetic exchange is considered, and Gaussian tails appear instead.
Article
Physics, Multidisciplinary
Timo Graesser, Philip Bleicker, Dag-Bjoern Hering, Mohsen Yarmohammadi, Goetz S. Uhrig
Summary: A dynamic mean-field theory for spin ensembles at infinite temperatures on arbitrary lattices has been established, showing the effectiveness of capturing the environment of each spin with a classical time-dependent random mean field. The approach provides a quantitative understanding of spin ensembles with dipolar interaction and static Gaussian noise, demonstrating its versatility and potential for further extensions.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Physics, Multidisciplinary
Mohsen Hafez-Torbati, Davide Bossini, Frithjof B. Anders, Goetz S. Uhrig
Summary: The Mott gap in insulators is affected by long-range antiferromagnetic order, resulting in a magnetic blue shift (MBS). In systems with localized spins, the double-exchange mechanism also contributes to the MBS. The coupling between spin and charge degrees of freedom has the potential to enable spin-to-charge conversion in Mott systems on extreme time scales.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Physics, Multidisciplinary
Brian Barch, Razieh Mohseninia, Daniel Lidar
Summary: The VZ model of quantum computation employs controllable Z-diagonal Hamiltonians in the presence of an external X field, achieving universality in one dimension with a gate set of O(1) depth overhead; its output distribution cannot be classically simulated, offering a low-resource method of demonstrating quantum supremacy.
PHYSICAL REVIEW RESEARCH
(2021)
Review
Physics, Applied
E. J. Crosson, D. A. Lidar
Summary: Optimization, sampling, and machine learning are key topics in quantum computing. Quantum annealing (QA) is a widely used heuristic algorithm for optimization and sampling. Continued exploration and development of algorithms within the QA framework show promising routes to achieve quantum enhancement.
NATURE REVIEWS PHYSICS
(2021)
