Article
Computer Science, Interdisciplinary Applications
Zhishen Huang, Stephen Becker
Summary: The study demonstrates that sketching can be used to compress simulation data and accurately estimate time autocorrelation and power spectral density, with higher accuracy compared to previous methods. Applying sketching to a molecular dynamics simulation of methanol showed that the estimate of spectral density is 90% accurate using only 10% of the data.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Jonathan N. Hallen, Santiago A. Grigera, D. Alan Tennant, Claudio Castelnovo, Roderich Moessner
Summary: In this study, a emergent dynamical fractal in a disorder-free, stoichiometric, and three-dimensional magnetic crystal is identified. This observation explains the anomalous exponent and rapidly diverging relaxation time in spin ice compounds.
Article
Multidisciplinary Sciences
Zachary R. Fox, Eli Barkai, Diego Krapf
Summary: Interpreting experimental data from single-particle tracking experiments is challenging. The authors proposed a new method based on power spectrum to determine the dynamics of stochastic motion of molecules. They used the aging Wiener-Khinchin theorem to derive the power spectral density of fractional Brownian motion coexisting with a scale-free continuous time random walk.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Masahiro Kamada, Antti Laitinen, Weijun Zeng, Marco Will, Jayanta Sarkar, Kirsi Tappura, Heikki Seppa, Pertti Hakonen
Summary: The study found that adsorbed O-2 molecules contribute significantly to flux noise in superconducting quantum interference devices, while 1/f(gamma) noise is caused by surface diffusion of Ne atoms and temporary formation of Ne clusters.
Article
Physics, Multidisciplinary
Nicola Molinari, Yu Xie, Ian Leifer, Aris Marcolongo, Mordechai Kornbluth, Boris Kozinsky
Summary: The method uses spectral decomposition of short-time ionic displacement covariance to accelerate computations of ionic conductivity and reduce uncertainty. It demonstrates robustness through mathematical and numerical proofs, and is applied to realistic electrolyte materials.
PHYSICAL REVIEW LETTERS
(2021)
Article
Mathematics, Interdisciplinary Applications
Richard F. Voss
Summary: Large-scale simulations and analysis confirm that the original powers of 2 geometric source sum algorithm accurately approximates an exact 1/f spectral density with a Gaussian amplitude distribution over any arbitrarily large frequency range. This computationally efficient incremental algorithm has a computation time that varies linearly with the number of generated samples after initialization. A new variation allows for non-integer and random ratios in the geometric sequence, reducing variations in the exact power-law spectral density and generating generalized 1/f(beta) noises by varying individual source amplitudes.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2022)
Article
Astronomy & Astrophysics
Antonino D' Alessandro, Luca Greco, Salvatore Scudero, Valentino Lauciani
Summary: This study assesses the spectral characteristics and spatio-temporal variability of seismic noise at Italian Seismic Network sites. The analysis provides insights into noise power characteristics, temporal and spatial variations of background noise, correlations with natural and anthropogenic noise sources, and an empirical relationship between microseismic noise and geographical features. A new seismic noise model baseline has been established for the Italian territory.
EARTH AND SPACE SCIENCE
(2021)
Article
Physics, Fluids & Plasmas
Andrew D. Maris, Bibek Pokharel, Sharan Ganjam Seshachallam, Moses Z. R. Misplon, Arjendu K. Pattanayak
Summary: The study employs spatial complexity metrics and temporal complexity metrics to isolate the effect of the environment on quantum-classical differences, revealing a parametrically invariant meta-attractor at a specific length scale where noise-added classical models strongly deviate from quantum dynamics. The research also generalizes the surprising result that classically regular orbits can exhibit the greatest quantum-classical differences in the semiclassical regime, showing that the dynamical growth of such differences is not determined by the degree of classical chaos.
Article
Engineering, Multidisciplinary
Lukasz Ciura, Jaroslaw Wrobel, Jacek Boguski, Jerzy Wrobel
Summary: This article demonstrates the use of the coherence function to analyze 1/f noise sources in a planar semiconductor structure with multiple electrical contacts. The study includes noise and coherence function measurements, the development of a 1/f noise model for the sample, theoretical calculations of the coherence function, and a comparison of theoretical and experimental values. The results show that the model, which assumes no 1/f noise from the bulk semiconductor and only 1/f noise from contacts, can effectively explain the experimental measurements of coherence. This method provides a straightforward interpretation and avoids the need for complex model parameters, unlike models based solely on power spectral density.
Article
Engineering, Multidisciplinary
Irma Uriarte, Daniela M. Martinez, Angel G. Andrade, Guillermo Galaviz, Norma A. Barboza
Summary: Spectrum sensing is the identification of unused license bands in Cognitive Radio Networks. Energy Detection (ED) is the most studied form of spectrum sensing, but its performance is significantly degraded by noise uncertainty. To enhance the robustness of ED in noise uncertainty scenarios, this study proposes the use of an adaptive detection threshold, calculated from the noise power estimate obtained at each sensing interval. The noise power estimate is obtained using the Spectral Minima Tracking (SMT) technique, and a correlation analysis is conducted to optimize the parameters of the SMT technique and improve the quality of the noise power estimate.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Masoumeh Aqamolaei, Mohammad Mahdi Ahmadi
Summary: This paper presents a new equation for modeling the phase noise spectrum of an oscillator, which is able to simulate both 1/f(2) and 1/f(3) regions. The effectiveness of the model is verified through mathematical analysis on the influence of oscillator phase noise on the performance of a continuous-time delta-sigma modulator, showing that the proposed equation can accurately predict this effect.
ELECTRONICS LETTERS
(2022)
Article
Engineering, Multidisciplinary
Daner Abdula, Tilak R. Thapaliya
Summary: This study compares the impact of contact resistance (R-c) on 1/f noise measurements using a traditional two-point probe (2pp) method and a novel three-point probe (3pp) method. The results show that using indium can significantly decrease the noise spectral density (NSD) in the 2pp configuration, and the 3pp configuration further reduces NSD, regardless of indium use. The 3pp method avoids the impact of R-c on NSD and provides a better noise floor for NSD testing compared to the convoluted signal in the 2pp arrangement.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2023)
Article
Physics, Applied
M. Mihaila, S. Dinulescu, P. Varasteanu
Summary: In topological insulators, the 1/f noise intensity shows intriguing peaks at specific temperatures. The microscopic origin of this noise structure was investigated by comparing it with the phonon density of states and Raman spectrum of each topological insulator. The noise peaks in (Bi,Sb)(2)Te-3 were found to track the van Hove singularities in the phonon density of states, with the most intense peak attributed to the thermal motion of Bi atoms. The increase in noise observed in (Bi,Sb)(2)Te-3 and BiSbTeSe1.6 above a certain temperature threshold is due to the strengthening of carrier-phonon coupling induced by anharmonicity. The Raman spectrum of a structurally similar topological insulator (BiSbTeSe2) mirrors all noise singularities, indicating that carrier-phonon interaction is the only source of 1/f fluctuations in topological insulators. These results suggest that the microscopic origin of 1/f noise in solids is the perpetual thermal motion of atoms.
APPLIED PHYSICS LETTERS
(2023)
Article
Quantum Science & Technology
M. Carroll, S. Rosenblatt, P. Jurcevic, I Lauer, A. Kandala
Summary: Superconducting qubits, as a leading candidate for quantum computing, exhibit fluctuations in their energy relaxation times (T-1), which can cause instabilities in device performance. This study introduces a technique to probe the spectral and temporal dynamics of T-1 and discovers strong correlations between the mean T-1 and a snapshot of T-1 over a specific frequency range, offering a promising approach for rapid T-1 characterization.
NPJ QUANTUM INFORMATION
(2022)
Article
Physics, Multidisciplinary
Kamiel Janssens, Guillaume Boileau, Marie-Anne Bizouard, Nelson Christensen, Tania Regimbau, Nick van Remortel
Summary: Several proposed gravitational wave interferometers, including the Einstein Telescope and Laser Interferometer Space Antenna, have a triangular configuration that allows for the construction of a unique null channel insensitive to gravitational waves from all directions. This study expands on previous work and explains how to estimate the power spectral density for non-identical and correlated noise sources in Einstein Telescope interferometers using the null channel formalism. The formalism is demonstrated with two examples that increase in complexity and realism. Known mixtures of noises are used to show the mathematical correctness and internal consistency of the formalism. Future research is highlighted to incorporate this formalism into a Bayesian estimation framework.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Chemistry, Physical
S. Ramirez-Hinestrosa, H. Yoshida, L. Bocquet, D. Frenkel
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Mechanics
S. Marbach, H. Yoshida, L. Bocquet
JOURNAL OF FLUID MECHANICS
(2020)
Article
Physics, Multidisciplinary
Antoine Laine, Antoine Nigues, Lyderic Bocquet, Alessandro Siria
Review
Mechanics
Nikita Kavokine, Roland R. Netz, Lyderic Bocquet
Summary: Nanofluidics has become a new field in fluid mechanics, exploring novel properties in fluids at the nanoscale; Recent advancements in fabrication technology have led to the design of artificial nanofluidic systems at the scale of biological nanopores, driving the development of new experimental techniques and theoretical tools; This review serves as a toolbox for studying fluids at the nanometer scale, presenting basic equations, breakdown of equations, and emergence of new properties in molecular-scale confinement.
ANNUAL REVIEW OF FLUID MECHANICS, VOL 53
(2021)
Article
Physics, Fluids & Plasmas
Simon Gravelle, Catherine Kamal, Lorenzo Botto
Summary: This study used molecular dynamics simulations to investigate the shear-induced rotational dynamics of freely suspended nanographene in a liquid. It was found that due to a finite hydrodynamic slip at the molecular surface, these flat molecules tend to align with a constant orientation angle rather than performing classical periodic orbits. Results for different Peclet numbers were compared to a theory developed for rigid axisymmetric particles, and the reduction in specific viscosity due to slip was explored when multiple nanographenes were suspended in the liquid.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Mechanics
Catherine Kamal, Simon Gravelle, Lorenzo Botto
Summary: This article focuses on the orientational dynamics of thin rigid platelets in shear flow, solving the Fokker-Plank equation and conducting boundary integral simulations for analysis. A threshold Peclet number Pe(c) is quantified, above which alignment occurs, and there is a regime where Brownian fluctuations can break alignment with rotation period dependent on the slip length.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Multidisciplinary Sciences
Paul Robin, Nikita Kavokine, Lyderic Bocquet
Summary: Recent advances in nanofluidics have allowed for the confinement of water to a single molecular layer, showing potential for bioinspired functionalities through molecular control of ion transport. However, the understanding of ion dynamics in these systems is still limited. Research has shown that significant nonlinear effects in ion transport across quasi-two-dimensional slits can lead to the memristor effect, which may be used to build elementary neurons.
Article
Physics, Fluids & Plasmas
Catherine Kamal, Simon Gravelle, Lorenzo Botto
Summary: In this study, a two-dimensional fluid-structure interaction model is developed to investigate the effect of bending deformation on the dynamics of flexible platelike particles with large interfacial slip in a shear flow. The results show that a stable alignment occurs even for relatively flexible particles, and edge effects on the shape of the plate are important for length-to-thickness aspect ratios as large as 100. This research is particularly relevant for understanding the hydrodynamics of suspended flexible sheets made of 2D nanomaterials.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Chemistry, Physical
Etienne Mangaud, Marie-Laure Bocquet, Lyderic Bocquet, Benjamin Rotenberg
Summary: Controlling electrokinetic transport through carbon and hexagonal boron nitride nanotubes proves to be significant for nanofluidic approaches in energy production, water desalination, etc. Different behaviors of hydroxide ions are identified on carbon and hBN surfaces, leading to different transport properties. The results emphasize the importance of considering the sorption mode of hydroxide ions in analyzing interfacial transport properties.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Simon Gravelle, Lorenzo Botto
Summary: The study found that the adsorption energy of graphene-oxide particles is not only dependent on the number of surface oxygen groups, but also on their distribution. In highly oxidized conditions, particle-particle interactions hinder the adsorption of new particles; whereas in low oxidation conditions, clustering and stacking of particles promote the adsorption of new particles.
Article
Multidisciplinary Sciences
Nikita Kavokine, Marie-Laure Bocquet, Lyderic Bocquet
Summary: This study develops a quantum theory of the solid-liquid interface, revealing a new contribution to friction due to the coupling of charge fluctuations in the liquid to electronic excitations in the solid. The research demonstrates a marked difference in quantum friction between the water-graphene and water-graphite interface, potentially explaining the radius-dependent slippage of water in carbon nanotubes.
Article
Chemistry, Physical
Simon Gravelle, Christian Holm, Alexander Schlaich
Summary: This study used molecular simulations to investigate the transport properties of thin water films on salt and soil interfaces. It found two distinct regimes for water transport, with different permeance depending on the water coverage and hydrogen bonding. The study also examined the effect of atomic surface defects on the transport properties and determined the humidity-dependent crossover between different transport regimes in porous materials.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Simon Gravelle, David Beyer, Mariano Brito, Alexander Schlaich, Christian Holm
Summary: NMR relaxometry is a powerful experimental approach for studying dynamic processes in soft matter systems. All-atom simulations provide detailed insights but are limited in modeling long polymer chains or hydrogels, while coarse-graining can overcome this limitation but sacrifices atomistic details. This study investigates the dipolar relaxation rates of a PEG-H2O mixture at both all-atom and coarse-grained levels, revealing that the coarse-grained results exhibit similar trends but with a systematic offset due to the absence of intramonomer component and imprecise positioning of spin carriers. The offset can be corrected by reconstructing atomistic details from the coarse-grained trajectories.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Multidisciplinary
Simon Gravelle, Sabina Haber-Pohlmeier, Carlos Mattea, Siegfried Stapf, Christian Holm, Alexander Schlaich
Summary: Through nuclear magnetic relaxation dispersion measurements, we explore the dynamic properties of water within salt crusts, specifically sodium chloride (NaCl) and sodium sulfate (Na2SO4). Our findings indicate that sodium sulfate salt crusts exhibit a higher frequency-dependent relaxation time T (1) than sodium chloride salt crusts. Molecular dynamics simulations further demonstrate that pore size and salt concentration significantly affect the value of T (1). These simulations shed light on the interplay between ion adsorption, water structure near the interface, and dispersion of T (1) at low frequency, which can be attributed to adsorption-desorption events.
Article
Chemistry, Physical
Adyant Agrawal, Simon Gravelle, Catherine Kamal, Lorenzo Botto
Summary: Combining molecular dynamics and continuum simulations, this study investigates the dynamics of peeling front in a system of multilayered graphene nanosheets immersed in water. The results show that the shape of the sheet is approximately independent of the pulling velocity.
