Article
Physics, Fluids & Plasmas
Sara Levay, David Fischer, Ralf Stannarius, Ellak Somfai, Tamas Borzsonyi, Lothar Brendel, Janos Torok
Summary: The study introduced a simple system to analyze the statistical properties of jammed granular ensembles and test Edwards' theory. Results showed that in a coupled system of two subsystems with different properties, the system must be considered as a single entity to be described by Edwards' theory, as constraints in stresses lead to counterintuitive effects.
Article
Physics, Multidisciplinary
Anurag Anshu, Srinivasan Arunachalam, Tomotaka Kuwahara, Mehdi Soleimanifar
Summary: This research demonstrates that learning the Hamiltonian of a quantum system only requires a polynomial number of local measurements. By establishing the strong convexity of the absolute value of finite-temperature free energy with respect to interaction coefficients in quantum many-body systems, the study provides a theoretical foundation for applying machine learning techniques to quantum Hamiltonian learning.
Article
Multidisciplinary Sciences
Timothy C. Stutz, Alfonso Landeros, Jason Xu, Janet S. Sinsheimer, Mary Sehl, Kenneth Lange
Summary: Interacting Particle Systems (IPSs) are simplified to well-mixed Chemical Reaction Networks (CRNs) using an algorithmic framework, allowing for a wide range of techniques to be applied. The approach is implemented in Julia and applied to complex spatial stochastic phenomena, aiding in standardizing mathematical models and generating hypotheses based on observed spatial phenomena.
Article
Physics, Multidisciplinary
Christopher W. Lynn, Caroline M. Holmes, William Bialek, David J. Schwab
Summary: We demonstrate that the evidence for a local arrow of time can be decomposed into irreversibility arising from individual dynamics and correlations among variables. Through models and neural activity analysis, we find that interactions between pairs of neurons contribute primarily to the irreversibility of neural activity.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Fluids & Plasmas
Christopher W. Lynn, Caroline M. Holmes, William Bialek, David J. Schwab
Summary: This article explores the generation mechanism of the arrow of time in living systems. By decomposing the entropy production of thermodynamic systems, the local evidence is found to consist of two independent terms and an interaction term. Using tools from nonequilibrium physics, the interaction term is further decomposed into contributions from pairs of elements. It is discovered that the interactions among pairs of neurons play a significant role in breaking detailed balance.
Article
Statistics & Probability
Edward L. Ionides, Kidus Asfaw, Joonha Park, Aaron A. King
Summary: Bagging, the combination of bootstrap estimators, is applied to infer from noisy or incomplete measurements in a collection of interacting stochastic dynamic systems. This paper introduces the bagged filter (BF) methodology, which utilizes spatiotemporally localized weights to select successful filters. The BF method outperforms other filters in modeling infectious disease transmission.
JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION
(2023)
Article
Biology
Irene Cogliati Dezza, Axel Cleeremans, William H. Alexander, David Badre
Summary: This study uses computational modeling, model-based functional magnetic resonance imaging analysis, and a novel experimental paradigm to identify a dedicated and independent value system for information in the human PFC. The results provide empirical evidence for PFC as an optimizer of independent information and reward signals during decision-making.
Article
Optics
Darvin Wanisch, Stephan Fritzsche
Summary: In the nonequilibrium dynamics of the XY spin chain with asymptotically decaying interactions, the localization or delocalization of quantum information depends on the speed of interaction decay. Fast interaction decay leads to delocalized quantum information requiring global measurements, while slow decay allows for quasi-instantaneous propagation but mainly accessible by local measurements at early times. Our findings suggest that entanglement is the dominant correlation in fast decay scenarios, whereas it takes some time for correlations to become monogamous in slow decay scenarios.
Article
Physics, Multidisciplinary
Fabio Mueller, Henrik Christiansen, Stefan Schnabel, Wolfhard Janke
Summary: We present a fast, hierarchical, and adaptive algorithm for Metropolis Monte Carlo simulations of systems with long-range interactions that reproduces the dynamics of a standard implementation exactly. The method allows for nonequilibrium studies and has been demonstrated for various systems in two dimensions. The measured run times support an average complexity O(N log N), with small prefactors resulting in speedup factors larger than 104. This general method enables the treatment of large systems that were previously inaccessible and may lead to a better understanding of physical phenomena rooted in long-range interactions.
Review
Physics, Multidisciplinary
Apoorva Nagar, Shamik Gupta
Summary: We review recent work on systems with multiple interacting-particles having the dynamical feature of stochastic resetting. The interplay of time scales related to inter-particle interactions and resetting leads to a rich behaviour, both static and dynamic. The presence of multiple particles also opens up a new possibility for the resetting dynamics itself, namely, that of different particles resetting all together (global resetting) or independently (local resetting).
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2023)
Article
Mathematics, Applied
Zhenfu Wang, Xianliang Zhao, Rongchan Zhu
Summary: In this paper, we consider the asymptotic behavior of the fluctuations for the empirical measures of interacting particle systems with singular kernels. We prove the convergence of the sequence of fluctuation processes to a generalized Ornstein-Uhlenbeck process. Our result extends classical results to singular kernels, including the Biot-Savart law, and applies to the point vortex model approximating the 2D incompressible Navier-Stokes equation and the 2D Euler equation. We also show that the limiting Ornstein-Uhlenbeck process is Gaussian and has optimal regularity. The method relies on the martingale approach and the Donsker-Varadhan variational formula, and involves estimating exponential integrals using cancellations and combinatorics techniques, which is of the type of the large deviation principle.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2023)
Article
Computer Science, Interdisciplinary Applications
Esther S. Daus, Markus Fellner, Ansgar Juengel
Summary: A random-batch method for interacting particle systems is proposed, which can be used for multicomponent systems. This method reduces the computational cost by randomly dividing particles into batches while maintaining a certain accuracy. The numerical efficiency of this method is confirmed through testing and simulations.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Tomotaka Kuwahara, Keiji Saito
Summary: This study disproves fast scrambling in generic long-range interacting systems with alpha > D, where the OTOC shows a polynomial growth over time as long as alpha > D and the necessary scrambling time over a distance R is larger than t greater than or similar to R[(2 alpha-2D)/(2 alpha-D+1)].
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
G. A. Dominguez-Castro, R. Paredes
Summary: We report a robust delocalization transition of a pair of hard-core bosons moving in a one-dimensional quasicrystal with power-law hopping, where quasiperiodicity suppresses transport in the regime of strong interactions before enhancing it when the quasiperiodic modulation is increased. By introducing an effective Hamiltonian for strong interactions, we uncover the mechanism behind the delocalization transition. Stationary single-particle properties and two-particle correlations confirm our findings.
Article
Statistics & Probability
Arianna Giunti, Chenlin Gu, Jean-Christophe Mourrat
Summary: This study demonstrates the algebraic convergence of finite-volume approximations of the bulk diffusion matrix for interacting particle systems in continuous space. The models considered are reversible with respect to Poisson measures of constant density and are of nongradient type. The study also introduces modified Caccioppoli and multiscale Poincare inequalities of independent interest.
ANNALS OF PROBABILITY
(2022)
Article
Physics, Mathematical
J. Haferkamp, F. Montealegre-Mora, M. Heinrich, J. Eisert, D. Gross, I Roth
Summary: Many quantum information protocols require the use of random unitaries, and unitary t-designs are often used as an alternative to Haar-random unitaries. In this work, we explore the non-Clifford resources needed to break the limitation of only being able to implement up to 3-designs with Clifford operations. We find that injecting a certain number of non-Clifford gates into a random Clifford circuit can produce an epsilon-approximate t-design, regardless of the system size. We also derive new bounds on the convergence time of random Clifford circuits to the t-th moment of the uniform distribution on the Clifford group.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
M. Hinsche, M. Ioannou, A. Nietner, J. Haferkamp, Y. Quek, D. Hangleiter, J. -P. Seifert, J. Eisert, R. Sweke
Summary: The task of learning a probability distribution from samples is common in the natural sciences. This study extensively characterizes the learnability of output distributions from local quantum circuits. The results show that Clifford circuit output distributions are efficiently learnable, but the injection of a single T gate makes density modeling task difficult. Additionally, generative modeling of universal quantum circuits is hard for any learning algorithm, classical or quantum, indicating no quantum advantage for probabilistic modeling tasks.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
Mohammadamin Tajik, Marek Gluza, Nicolas Sebe, Philipp Schuettelkopf, Federica Cataldini, Joao Sabino, Frederik Moller, Si-Cong Ji, Sebastian Erne, Giacomo Guarnieri, Spyros Sotiriadis, Jens Eisert, Jorg Schmiedmayer
Summary: We investigate signal propagation in a quantum field simulator of the Klein-Gordon model using two strongly coupled parallel one-dimensional quasi-condensates. We observe the propagation of correlations along sharp light-cone fronts by measuring local phononic fields after a quench. The curved propagation fronts and reflection at sharp edges are observed when the local atomic density is inhomogeneous. By comparing the data with theoretical predictions, we find agreement with curved geodesics of an inhomogeneous metric.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Quantum Science & Technology
Johannes Jakob Meyer, Marian Mularski, Elies Gil-Fuster, Antonio Anna Mele, Francesco Arzani, Alissa Wilms, Jens Eisert
Summary: Variational quantum machine learning is a widely studied application of near-term quantum computers. This work explores how symmetries of the learning problem can be used to construct quantum learning models with symmetrical outcomes. By utilizing tools from representation theory, a standard gateset can be transformed into an equivariant gateset that respects the symmetries of the problem. The proposed methods are benchmarked on toy problems and show a substantial increase in generalization performance.
Article
Physics, Multidisciplinary
Mingru Yang, Bram Vanhecke, Norbert Schuch
Summary: New or enlarged symmetries can emerge at the low-energy spectrum of a Hamiltonian that does not possess the symmetries, if the symmetry breaking terms in the Hamiltonian are irrelevant under the renormalization group flow. We propose a tensor network based algorithm to numerically extract lattice operator approximation of the emergent conserved currents from the ground state of any quantum spin chains, without the necessity to have prior knowledge about its low-energy effective field theory. Our results for the spin-1/2 J-Q Heisenberg chain and a one-dimensional version of the deconfined quantum critical points demonstrate the power of our method to obtain the emergent lattice Kac-Moody generators. It can also be viewed as a way to find the local integrals of motion of an integrable model and the local parent Hamiltonian of a critical gapless ground state.
PHYSICAL REVIEW LETTERS
(2023)
Review
Physics, Multidisciplinary
Dominik Hangleiter, Jens Eisert
Summary: Quantum random sampling is the main proposal to demonstrate the computational advantage of quantum computers over classical computers. Recent large-scale implementations of quantum random sampling have possibly surpassed the capabilities of existing classical hardware for simulation. This review comprehensively discusses the theoretical basis and practical implementation of quantum random sampling, as well as its classical simulation, and explores open questions and potential applications in the field.
REVIEWS OF MODERN PHYSICS
(2023)
Article
Multidisciplinary Sciences
J. Helsen, M. Ioannou, J. Kitzinger, E. Onorati, A. H. Werner, J. Eisert, I. Roth
Summary: With quantum computing devices becoming more complex, there is a need for tools that can provide precise diagnostic information about quantum operations. The authors propose a new approach that uses random gate sequences and native measurements followed by classical post-processing to estimate various gate set properties. They also discuss applications for optimizing quantum gates and diagnosing cross-talk. This research is important for the development and improvement of quantum computing devices.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
F. H. B. Somhorst, R. van der Meer, M. Correa Anguita, R. Schadow, H. J. Snijders, M. de Goede, B. Kassenberg, P. Venderbosch, C. Taballione, J. P. Epping, H. H. van den Vlekkert, J. Timmerhuis, J. F. F. Bulmer, J. Lugani, I. A. Walmsley, P. W. H. Pinkse, J. Eisert, N. Walk, J. J. Renema
Summary: This study demonstrates that in a unitarily evolving system, single-mode measurements can converge to a thermal state using photons in an integrated optical interferometer. The resolution to the paradox between unitary evolution and the second law of thermodynamics is the recognition that the global unitary evolution of a multi-partite quantum state causes local subsystems to evolve towards maximum-entropy states. The experiment utilizes a programmable integrated quantum photonic processor to manipulate quantum states and shows the potential of photonic devices for simulating non-Gaussian states.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Kerstin Beer, Megha Khosla, Julius Koehler, Tobias J. Osborne, Tianqi Zhao
Summary: In this paper, an approach is developed to improve learning efficiency by leveraging the graph structure of the quantum source for an arbitrary quantum neural network (QNN) ansatz. A self-supervised objective is devised and optimized to capture the information-theoretic closeness of quantum states during QNN training. Numerical simulations demonstrate that this approach enhances learning efficiency and generalization behavior of the base QNN. Moreover, scalable quantum implementations of the learning procedure described in this paper are likely feasible on the next generation of quantum computing devices.
Article
Quantum Science & Technology
Ingo Roth, Jadwiga Wilkens, Dominik Hangleiter, Jens Eisert
Summary: Extracting tomographic information about quantum states is crucial in developing high-precision quantum devices. This study shows that by exploiting the low-rank structure of quantum states, a scalable 'blind' tomography scheme can be achieved with a computationally efficient post-processing algorithm. The efficiency of the scheme is further improved by utilizing the sparse structure of the calibrations.
Article
Optics
Ivana Kurecic, Tobias J. Osborne
Summary: The dynamics of interacting quantum systems in the presence of disorder is studied and an exact representation for disorder-averaged quantities via Ito stochastic calculus is obtained. The stochastic integral representation allows for analytic approximation, potential applicability to interacting systems, and compatibility with tensor network methods. The integral can be expanded to produce a series of approximations, the first of which includes all diffusive corrections and is manifestly completely positive. As examples, expressions for the density of states and spectral form factor for the Anderson model are obtained.
Article
Optics
Niklas Pirnay, Ryan Sweke, Jens Eisert, Jean-Pierre Seifert
Summary: Density modeling is the task of learning an unknown probability density function from samples, and it is a central problem in unsupervised machine learning. This research demonstrates that fault-tolerant quantum computers can offer a superpolynomial advantage over classical learning algorithms in a specific density modeling problem, assuming standard cryptographic assumptions. The results also provide insights for future distribution learning separations between quantum and classical learning algorithms, including the relationship between hardness results in supervised learning and distribution learning.
Article
Materials Science, Multidisciplinary
Philipp Schmoll, Augustine Kshetrimayum, Jan Naumann, Jens Eisert, Yasir Iqbal
Summary: We investigate the ground state of the spin S = 1/2 Heisenberg antiferromagnet on the shuriken lattice, and found that a valence bond crystal with resonances over length six loops emerges as the ground state, yielding the lowest reported estimate of the ground state energy for this model. We also study the model in the presence of an external magnetic field and find the emergence of 0, 1/3, and 2/3 magnetization plateaus, with the 1/3 and 2/3 plateau states respecting translation and point group symmetries and featuring loop-four plaquette resonances.
Article
Quantum Science & Technology
Konstantin Tiurev, Peter-Jan H. S. Derks, Joschka Roffe, Jens Eisert, Jan-Michael Reiner
Summary: This study develops topological surface codes adapted to known noise structures and investigates their performance with specific decoders. Experimental results show that this approach significantly improves error thresholds and reduces failure rates. Furthermore, the study reveals the importance of tailored surface codes in correcting local noise.
Article
Quantum Science & Technology
Jarn de Jong, Frederik Hahn, Jens Eisert, Nathan Walk, Anna Pappa
Summary: Sharing multi-partite quantum entanglement allows for diverse secure communication tasks. In this work, an anonymous CKA protocol for three parties is proposed, implemented in a highly practical network setting using a linear cluster state among quantum nodes. The protocol protects the identities of the participants and contributes to identifying feasible quantum communication tasks for network architectures beyond point-to-point.
