For low emission currents from around 1 microA Ga liquid-metal ion sources (LMIS) produce fine optically bright ion beams that are strongly limited by the Coulomb particle-particle interactions. We present computations of the energy spread, the beam virtual crossover size, and beam brightness based on direct numerical integration of the equation of motion in a numerically calculated field for a number of dimensions of the emission tip. The Coulomb particle-particle interactions are included into the calculation of ion beam evolution. A comparison with experimental data allows to estimate the tip size.
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http://dx.doi.org/10.1016/j.ultramic.2007.07.004 | DOI Listing |
Neural Netw
August 2024
Department of Computer Science, University of Illinois at Chicago, United States of America.
The great learning ability of deep learning facilitates us to comprehend the real physical world, making learning to simulate complicated particle systems a promising endeavour both in academia and industry. However, the complex laws of the physical world pose significant challenges to the learning based simulations, such as the varying spatial dependencies between interacting particles and varying temporal dependencies between particle system states in different time stamps, which dominate particles' interacting behavior and the physical systems' evolution patterns. Existing learning based methods fail to fully account for the complexities, making them unable to yield satisfactory simulations.
View Article and Find Full Text PDFSoft Matter
June 2022
Condensed Matter Physics Laboratory, Heinrich Heine University, Universitätsstraße 1, 40225 Düsseldorf, Germany.
Confinement modifies the properties of a fluid. The particle density is no longer uniform but depends on the distance from the walls; parallel to the walls, layers with different particle densities form. This affects the particle packing in the layers.
View Article and Find Full Text PDFRep Prog Phys
September 2021
Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, 117546, Singapore.
Materials with thickness ranging from a few nanometers to a single atomic layer present unprecedented opportunities to investigate new phases of matter constrained to the two-dimensional plane. Particle-particle Coulomb interaction is dramatically affected and shaped by the dimensionality reduction, driving well-established solid state theoretical approaches to their limit of applicability. Methodological developments in theoretical modelling and computational algorithms, in close interaction with experiments, led to the discovery of the extraordinary properties of two-dimensional materials, such as high carrier mobility, Dirac cone dispersion and bright exciton luminescence, and inspired new device design paradigms.
View Article and Find Full Text PDFJ Chem Theory Comput
April 2021
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.
Approximation of a tensor network by approximating (e.g., factorizing) one or more of its constituent tensors can be improved by canceling the leading-order error due to the constituents' approximation.
View Article and Find Full Text PDFJ Chem Phys
March 2021
Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Pune 411008, India.
We propose a novel model for a glass-forming liquid, which allows us to switch in a continuous manner from a standard three-dimensional liquid to a fully connected mean-field model. This is achieved by introducing k additional particle-particle interactions, which thus augments the effective number of neighbors of each particle. Our computer simulations of this system show that the structure of the liquid does not change with the introduction of these pseudo-neighbors and by means of analytical calculations, and we determine the structural properties related to these additional neighbors.
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