Review
Physics, Multidisciplinary
Chandan Datta, Tulja Varun Kondra, Marek Miller, Alexander Streltsov
Summary: This article discusses the concept of catalysts and their applications in both chemistry and quantum fields. It focuses on the recent developments in quantum catalysis and the study of phenomena such as quantum entanglement, coherence, and thermodynamics.
REPORTS ON PROGRESS IN PHYSICS
(2023)
Article
Mechanics
Zacharias Roupas
Summary: Louis de Broglie attempted to address the problem of time in quantum theory by introducing sub-quantum degrees of freedom and relying on statistical thermodynamics. His conjecture, along with Mandelbrot's derivation, reveals a connection between energy, temperature, and the quantum time-energy uncertainty relation.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2021)
Article
Physics, Multidisciplinary
Durga Bhaktavatsala Rao Dasari
Summary: We use exact calculations to analyze the thermodynamical effects of depolarizing a zero-temperature quantum spin-bath with a quantum probe coupled to an infinite temperature bath. The induced correlations in the bath during the depolarizing process prevent the bath's entropy from increasing to its maximum limit, but the energy deposited in the bath can be extracted completely in a finite time. We investigate these findings using a solvable central spin model, demonstrating that destroying unwanted correlations enhances the rate of energy extraction and entropy towards their limiting values. These studies have implications for quantum battery research, particularly in understanding battery performance during charging and discharging processes.
Article
Quantum Science & Technology
Robert Starek, Michal Micuda, Michal Kolar, Radim Filip, Jaromir Fiurasek
Summary: In this study, conditional enhancement of overall coherence of quantum states was investigated through probabilistic quantum operations that utilize a quantum filter diagonal in the basis of incoherent states. Optimal filters were identified to maximize output coherence for a given probability of successful filtering. Through a proof-of-principle experiment with linear optics, the performance of the studied quantum filters was verified and optimal quantum coherence enhancement by quantum filtering was observed.
QUANTUM SCIENCE AND TECHNOLOGY
(2021)
Article
Chemistry, Applied
Forrest H. Kaatz, Adhemar Bultheel
Summary: This study investigates nanocatalysis using density functional theory, statistical mechanics, and thermodynamics, finding size effects for nanoclusters between 3 and 9 nm. Despite modeling three different systems, only small differences in the large-scale entropy and enthalpy of the nanoclusters were observed. Shape effects are predicted to be greatest for nanoclusters of size 10 nm.
Article
Physics, Multidisciplinary
Markus Rademacher, Michael Konopik, Maxime Debiossac, David Grass, Eric Lutz, Nikolai Kiesel
Summary: This study verifies the validity of fluctuation theorems in the presence of simultaneous mechanical and thermal changes by implementing fast and controlled temperature variations using feedback cooling techniques.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Maxwell Aifer, Sebastian Deffner
Summary: This article studies the energetically optimal implementation of quantum operations. By using the framework of quantum speed limits, we find the universally optimal solutions for single and N-qubit operations.
NEW JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Martin Alpert
Summary: A new quantum mechanics mechanism theory based on statistical mechanics is introduced in this article to explain the relationship between energy changes and state changes during the observation process. Two experiments are proposed to validate the theory and it is anticipated that the validation will further enhance the understanding of the measurement process and entanglement.
FRONTIERS IN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Moises Rojas, Iarley P. Lobo
Summary: This paper investigates the influence of a thermal bath on quantum correlations induced by gravitational interaction between two massive cat states. The results demonstrate that increasing the masses or decreasing the distance between them can significantly optimize the thermal concurrence and l(1)-norm.
Article
Physics, Multidisciplinary
Jae Sung Lee, Sangyun Lee, Hyukjoon Kwon, Hyunggyu Park
Summary: Landauer's bound is the minimum thermodynamic cost for erasing one bit of information. Finite-time operation incurs additional energetic costs, with different scaling behavior depending on the degree of irreversibility of the process. Optimal dynamics can lead to the equality of the bound.
PHYSICAL REVIEW LETTERS
(2022)
Article
Quantum Science & Technology
Guilherme L. Zanin, Michael Antesberger, Maxime J. Jacquet, Paulo H. Souto Ribeiro, Lee A. Rozema, Philip Walther
Summary: Maxwell's Demon is at the heart of the relationship between quantum information processing and thermodynamics; photonic experiments offer great potential for exploring new regimes in quantum thermodynamics.
Article
Multidisciplinary Sciences
Tomas Opatrny, Simon Brauer, Abraham G. Kofman, Avijit Misra, Nilakantha Meher, Ofer Firstenberg, Eilon Poem, Gershon Kurizki
Summary: We propose heat machines that are nonlinear, coherent, and closed systems composed of few field modes. These machines can transform thermal-state input into nonthermal output with controlled quantum fluctuations, providing an output with reduced uncertainty that may be useful for sensing or communications in the quantum domain. They can be realized in optomechanical cavities or cold gases where interactions between photons or atoms are utilized.
Article
Physics, Multidisciplinary
Takahiro Sagawa, Philippe Faist, Kohtaro Kato, Keiji Matsumoto, Hiroshi Nagaoka, Fernando G. S. L. Brandao
Summary: The study demonstrates that for quantum spin systems with a local, translation-invariant Hamiltonian, asymptotic state convertibility from one quantum state to another using thermal operations is characterized by the KL divergence rate for translation-invariant and spatially ergodic states. The proof is divided into two parts and utilizes the resource theory from quantum information theory. This result highlights the significance of the KL divergence rate as a thermodynamic potential for describing thermodynamic convertibility of ergodic states of quantum many-body systems in the thermodynamic limit.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Thomas Guff, Nathan A. McMahon, Yuval R. Sanders, Alexei Gilchrist
Summary: The study focuses on formal resource theory of quantum measurements, showing that protocols like catalysis and purification are impossible in this theory. Standard measures of information gain are proven to be resource monotones, and the resource theory is applied to quantum state discrimination tasks.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Fluids & Plasmas
Juan P. Garrahan, Felix Ritort
Summary: We introduce a family of generalized continuous Maxwell demons (GCMDs) that operate on idealized single-bit equilibrium devices, combining the single-measurement Szilard and the repeated measurements of the continuous Maxwell demon protocols. We derive cycle distributions for extracted work, information content, and time, and calculate power and information-to-work efficiency fluctuations for different models. We find that the efficiency at maximum power is highest for an opportunistic protocol of continuous type in the dynamical regime dominated by rare events. We also extend the analysis to finite-time work extracting protocols and show that dynamical finite-time correlations in this model increase the information-to-work conversion efficiency, highlighting the role of temporal correlations in optimizing information-to-energy conversion.
Article
Quantum Science & Technology
Alexander Jahn, Zoltan Zimboras, Jens Eisert
Summary: The study of critical quantum many-body systems through conformal field theory is an important field in modern quantum physics. Certain conformal field theory models have a duality with gravity theories in higher dimensions. In order to reproduce this duality, many discrete models based on tensor networks have been proposed. This study shows that the symmetries of these models are suitable for approximating conformal field theory states, introducing the concept of quasi-periodic conformal field theory.
Article
Mathematics, Applied
Axel Flinth, Benedikt Gross, Ingo Roth, Jens Eisert, Gerhard Wunder
Summary: Compressed sensing studies linear recovery problems with structure assumptions, introducing hierarchical measurement operators for efficient, stable and robust recovery of hierarchically structured signals. Bounds on their hierarchical restricted isometry properties are derived based on restricted isometry constants, extending prior work on Kronecker-product measurements. The HiHTP algorithm is shown to be suitable for solving communication scenarios, with numerical evaluation of sparse signal recovery and block detection capability.
APPLIED AND COMPUTATIONAL HARMONIC ANALYSIS
(2022)
Article
Physics, Multidisciplinary
Jonas Haferkamp, Philippe Faist, Naga B. T. Kothakonda, Jens Eisert, Nicole Yunger Halpern
Summary: The complexity of quantum states, which is key in quantum computing and black hole theory, has been shown to grow linearly over time under random operations. This study investigates how the complexity of random quantum circuits increases by constructing unitary operations from random two-qubit quantum gates. It is proven that the complexity grows linearly until it saturates at a threshold that is exponentially related to the number of qubits.
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.
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
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
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.
