Article
Multidisciplinary Sciences
Nicolo Defenu
Summary: In systems with power-law decaying couplings, the spectrum remains discrete up to the thermodynamic limit, unlike traditional results on the chaotic nature of spectra in many-body quantum systems. The existence of QSSs may be related to the finiteness of Poincare recurrence times, extending known results on anomalous magnetization dynamics in the quantum Ising model with power-law decaying couplings. The comparison between the discrete spectrum of long-range systems and more conventional examples of pure point spectra in the disordered case is also discussed.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Computer Science, Information Systems
Priya G. Dharshini, K. Sreenivasa Rao
Summary: This study aims to build effective accent recognition systems based on emotional speech. By applying statistical aggregation functions on different features and conducting experiments using clean and noisy speech signals, it is found that some features perform well on noisy data while the robustness of others depends on whether there is noisy training data.
MULTIMEDIA TOOLS AND APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Lizhong Wang, Pierre-Alain Fayolle, Alexander G. Belyaev
Summary: This paper proposes a modified approach for reverse image filtering using Landweber iterations. The method shows high robustness to noise and has potential applications in image deblurring and super-resolution.
SIGNAL IMAGE AND VIDEO PROCESSING
(2023)
Article
Computer Science, Artificial Intelligence
Orhun Bugra Baran, Ramazan Gokberk Cinbis
Summary: This paper investigates a key issue in few-shot learning, which is handling ambiguities resulting from having too few training samples per class. To address this problem, the authors propose a meta-learning model based on semantic knowledge, which leverages feature attention and sample attention mechanisms to improve the synthesis of classifiers.
Article
Physics, Multidisciplinary
Hans A. Weidenmueller
Summary: The Pauli master equation, which describes the statistical equilibration of a closed quantum system, is derived in this paper using concepts from quantum chaos and random-matrix theory. It is assumed that the system consists of subsystems with strong internal mixing, and the system is modeled as an ensemble of random matrices. Equilibration occurs through averaging over the ensemble, and the direction of time is determined by a weak coupling to the outside world.
Article
Physics, Multidisciplinary
Max McGinley, Sthitadhi Roy, S. A. Parameswaran
Summary: We propose a model of nonunitary quantum dynamics that exhibits infinitely long-lived discrete spatiotemporal order robust against any unitary or dissipative perturbation. By combining a sequence of projective measurements with a local feedback rule, ergodicity is evaded. The results are verified through numerical simulations and explicit experimental protocols.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Pavel Kos, Bruno Bertini, Tomaz Prosen
Summary: In this study, we investigate the time-evolution operator in a local quantum circuit with random fields, finding that quantum chaos leads to it effectively behaving as a random matrix in many-body quantum space at large times. By analyzing the squared magnitude of the trace of the evolution operator, known as the generalized spectral form factor, we compare our findings with random matrix theory predictions. Furthermore, we establish a connection between chaotic and ergodic properties of the systems through the realization that the generalized spectral form factor can be expressed in terms of dynamical correlation functions of local observables in the infinite temperature state. Additionally, we explore the relationship between the many-body Thouless time tau(th) and the conservation laws of the system, explaining the different scalings observed for systems with and without conservation laws.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Archak Purkayastha, Madhumita Saha, Bijay Kumar Agarwalla
Summary: This study reveals that a one-dimensional ordered fermionic lattice system connected to two baths with different chemical potentials at zero temperature exhibits two phases of subdiffusive conductance scaling with system size, unlike the perfectly ballistic transport in the isolated system. Interestingly, there are two chemical-potential-driven subdiffusive to ballistic phase transitions at zero temperature in the open system scenario.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Rafal A. Bogaczewicz, Pawel Machnikowski
Summary: This paper develops a general theory for resonance fluorescence (RF) in the low excitation limit and investigates the influence of two important types of noise processes on the RF spectrum. The study shows that different classes of noise affect the RF spectrum in a characteristic way, and the spectrum carries information about the noise characteristics present in the physical system.
NEW JOURNAL OF PHYSICS
(2023)
Article
Economics
Nidhaleddine Ben Cheikh, Younes Ben Zaied
Summary: This study investigates the impact of adverse geopolitical events on crude oil and clean energy markets. The findings show that crude oil market is unresponsive to geopolitical events, with a significant price spike only occurring when risks associated with tensions surpass a certain threshold. The green equity market, on the other hand, reacts negatively during episodes of higher geopolitical uncertainty. Furthermore, the study reveals a decoupling between traditional and clean energy sectors during times of geopolitical stress.
Article
Physics, Nuclear
Jean-Paul Blaizot, Li Yan
Summary: In this study, a plasma of massless particles undergoing Bjorken expansion is considered in the context of ultrarelativistic heavy ion collisions. The transition to hydrodynamics is investigated using kinetic theory and the relaxation time approximation. By analyzing a coupled mode problem and identifying an attractor solution, the speed and characteristics of the transition to hydrodynamics are explored. The accuracy of hydrodynamics, particularly in early time regions with large gradients, is highlighted as crucial for understanding the behavior of the system.
Article
Computer Science, Theory & Methods
Linghui Zhou, Minh Thanh Vu, Tobias J. Oechtering, Mikael Skoglund
Summary: This paper studies the fundamental trade-offs in privacy-preserving biometric identification systems with noisy enrollment, and introduces the concept of private keys to achieve close to zero privacy leakage rate. The results show that increasing the private key rate can enlarge the identification rate and secret key rate.
IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY
(2021)
Article
Geochemistry & Geophysics
Patrick Beaudry, Andri Stefansson, Jens Fiebig, Jeemin H. Rhim, Shuhei Ono
Summary: Research suggests that methane from geothermal areas can originate from thermal cracking of organic matter or have an abiotic origin, with geological features and fluid residence times influencing the isotopic equilibrium distribution of methane. Geothermal fields in Iceland exhibit higher temperatures and shorter fluid residence times, while Nisyros shows longer fluid residence times and equilibrium isotopic distributions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2021)
Article
Polymer Science
Katsumi Hagita, Takahiro Murashima
Summary: By simulating the properties of rings, it was found that an increase in the size of the rings leads to an increase in the number of linear chains penetrating the rings.
Article
Physics, Fluids & Plasmas
Pierpaolo Sgroi, Mauro Paternostro
Summary: We model the dynamics of a closed quantum system undergoing a spontaneous thermodynamic transformation. By considering the behavior of a quantum particle in a box with a moving and insulating wall, we obtain a set of differential equations that describe the evolution of the quantum system and the motion of the wall. Our approach captures multiple properties of the thermodynamic process and goes beyond traditional descriptions.
Article
Quantum Science & Technology
Jason M. Dominy, Lorenzo Campos Venuti, Alireza Shabani, Daniel A. Lidar
QUANTUM INFORMATION PROCESSING
(2017)
Article
Physics, Mathematical
Paolo Zanardi, Lorenzo Campos Venuti
JOURNAL OF MATHEMATICAL PHYSICS
(2018)
Article
Physics, Applied
Lorenzo Campos Venuti, Domenico D'Alessandro, Daniel A. Lidar
Summary: The text discusses the application of quantum computing in optimization, focusing on finding the optimal control schedule for quantum annealing (QA) and the quantum approximate optimization algorithm (QAOA). By rigorously analyzing the quantum optimal control problem within Pontryagin's maximum principle framework, the study extends previous findings to open systems and suggests that continuous schedules may be more suitable for practical quantum optimization in noisy experimental environments.
PHYSICAL REVIEW APPLIED
(2021)
Article
Physics, Applied
Humberto Munoz-Bauza, Lorenzo Campos Venuti, Daniel Lidar
Summary: The boundary-cancellation theorem extends the standard quantum adiabatic theorem and shows that the distance between a state prepared by a boundary-cancelling adiabatic protocol and the steady state of the system shrinks as a power of the number of vanishing time derivatives of the Hamiltonian. This theorem is further generalized to apply to cases where the Liouvillian gap vanishes, and the effect of dynamical freezing of the evolution is considered. Experimental tests using quantum annealing hardware confirm the predictions of the boundary-cancellation theorem and demonstrate its robustness compared to other protocols.
PHYSICAL REVIEW APPLIED
(2023)
Article
Optics
Yu Yao, Henning Schloemer, Zhengzhi Ma, Lorenzo Campos Venuti, Stephan Haas
Summary: This study explores topological protection mechanisms in dissipative quantum systems in the presence of quenched disorder to extend the coherence time of a fiducial qubit. It is found that under certain symmetries, a winding number can be defined and evaluated even in the presence of disorder, allowing for the construction of topological phase diagrams. In the presence of competing disorder parameters, interesting reentrance phenomena of topologically nontrivial sectors are observed, where increasing disorder drastically increases the coherence time of the fiducial qubit in certain parameter regions.
Article
Materials Science, Multidisciplinary
Georgios Styliaris, Namit Anand, Lorenzo Campos Venuti, Paolo Zanardi
Article
Optics
Jeffrey Marshall, Lorenzo Campos Venuti, Paolo Zanardi
Article
Optics
Lorenzo Campos Venuti, Daniel A. Lidar
Article
Optics
Michael Tomka, Lorenzo Campos Venuti, Paolo Zanardi
Article
Optics
Georgios Styliaris, Lorenzo Campos Venuti, Paolo Zanardi
Article
Optics
Jeffrey Marshall, Lorenzo Campos Venuti, Paolo Zanardi
Article
Optics
Lorenzo Campos Venuti, Zhengzhi Ma, Hubert Saleur, Stephan Haas
Article
Optics
Paolo Zanardi, Georgios Styliaris, Lorenzo Campos Venuti
Article
Optics
Paolo Zanardi, Georgios Styliaris, Lorenzo Campos Venuti
Article
Optics
Lorenzo Campos Venuti, Tameem Albash, Milad Marvian, Daniel Lidar, Paolo Zanardi