The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Gang Chen - One of the best experts on this subject based on the ideXlab platform.
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electron energy can oscillate near a Crystal Dislocation
New Journal of Physics, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:Crystal Dislocations govern the plastic mechanical properties of materials but also affect the electrical and optical properties. However, a fundamental and quantitative quantum field theory of a Dislocation has remained undiscovered for decades. Here we present an exactly-solvable one-dimensional quantum field theory of a Dislocation, for both edge and screw Dislocations in an isotropic medium, by introducing a new quasiparticle which we have called the 'dislon'. The electron-Dislocation relaxation time can then be studied directly from the electron self-energy calculation, which is reducible to classical results. In addition, we predict that the electron energy will experience an oscillation pattern near a Dislocation. Compared with the electron density's Friedel oscillation, such an oscillation is intrinsically different since it exists even with only single electron is present. With our approach, the effect of Dislocations on materials' non-mechanical properties can be studied at a full quantum field theoretical level.
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electron energy can oscillate near a Crystal Dislocation
IOP Publishing, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:United States. Department of Energy. Office of Science. Solid-State Solar Thermal Energy Conversion Center (Award DE-SC0001299/DE-FG02-09ER46577)
Enrico Valdinoci - One of the best experts on this subject based on the ideXlab platform.
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long time behavior for Crystal Dislocation dynamics
Mathematical Models and Methods in Applied Sciences, 2017Co-Authors: Stefania Patrizi, Enrico ValdinociAbstract:We describe the asymptotic states for the solutions of a nonlocal equation of evolutionary type, which have the physical meaning of the atom Dislocation function in a periodic Crystal. More precisely, we can describe accurately the “smoothing effect” on the Dislocation function occurring slightly after a “particle collision” (roughly speaking, two opposite transitions layers average out) and, in this way, we can trap the atom Dislocation function between a superposition of transition layers which, as time flows, approaches either a constant function or a single heteroclinic (depending on the algebraic properties of the orientations of the initial transition layers). The results are endowed with explicit and quantitative estimates and, as a byproduct, we show that the ODE systems of particles that govern the evolution of the transition layers does not admit stationary solutions (i.e. roughly speaking, transition layers always move).
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Dislocation Dynamics in Crystals: A Macroscopic Theory in a Fractional Laplace Setting
Communications in Mathematical Physics, 2014Co-Authors: Serena Dipierro, Giampiero Palatucci, Enrico ValdinociAbstract:We consider an evolution equation arising in the Peierls–Nabarro model for Crystal Dislocation. We study the evolution of such a Dislocation function and show that, at a macroscopic scale, the Dislocations have the tendency to concentrate at single points of the Crystal, where the size of the slip coincides with the natural periodicity of the medium. These Dislocation points evolve according to the external stress and an interior repulsive potential.
Mingda Li - One of the best experts on this subject based on the ideXlab platform.
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electron energy can oscillate near a Crystal Dislocation
New Journal of Physics, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:Crystal Dislocations govern the plastic mechanical properties of materials but also affect the electrical and optical properties. However, a fundamental and quantitative quantum field theory of a Dislocation has remained undiscovered for decades. Here we present an exactly-solvable one-dimensional quantum field theory of a Dislocation, for both edge and screw Dislocations in an isotropic medium, by introducing a new quasiparticle which we have called the 'dislon'. The electron-Dislocation relaxation time can then be studied directly from the electron self-energy calculation, which is reducible to classical results. In addition, we predict that the electron energy will experience an oscillation pattern near a Dislocation. Compared with the electron density's Friedel oscillation, such an oscillation is intrinsically different since it exists even with only single electron is present. With our approach, the effect of Dislocations on materials' non-mechanical properties can be studied at a full quantum field theoretical level.
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electron energy can oscillate near a Crystal Dislocation
IOP Publishing, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:United States. Department of Energy. Office of Science. Solid-State Solar Thermal Energy Conversion Center (Award DE-SC0001299/DE-FG02-09ER46577)
Albert C. S. Chung - One of the best experts on this subject based on the ideXlab platform.
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Nonrigid Image Registration With Crystal Dislocation Energy
IEEE Transactions on Image Processing, 2013Co-Authors: Albert C. S. ChungAbstract:The goal of nonrigid image registration is to find a suitable transformation such that the transformed moving image becomes similar to the reference image. The image registration problem can also be treated as an optimization problem, which tries to minimize an objective energy function that measures the differences between two involved images. In this paper, we consider image matching as the process of aligning object boundaries in two different images. The registration energy function can be defined based on the total energy associated with the object boundaries. The optimal transformation is obtained by finding the equilibrium state when the total energy is minimized, which indicates the object boundaries find their correspondences and stop deforming. We make an analogy between the above processes with the Dislocation system in physics. The object boundaries are viewed as Dislocations (line defects) in Crystal. Then the well-developed Dislocation energy is used to derive the energy assigned to object boundaries in images. The newly derived registration energy function takes the global gradient information of the entire image into consideration, and produces an orientation-dependent and long-range interaction between two images to drive the registration process. This property of interaction endows the new registration framework with both fast convergence rate and high registration accuracy. Moreover, the new energy function can be adapted to realize symmetric diffeomorphic transformation so as to ensure one-to-one matching between subjects. In this paper, the superiority of the new method is theoretically proven, experimentally tested and compared with the state-of-the-art SyN method. Experimental results with 3-D magnetic resonance brain images demonstrate that the proposed method outperforms the compared methods in terms of both registration accuracy and computation time.
Mildred S Dresselhaus - One of the best experts on this subject based on the ideXlab platform.
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electron energy can oscillate near a Crystal Dislocation
New Journal of Physics, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:Crystal Dislocations govern the plastic mechanical properties of materials but also affect the electrical and optical properties. However, a fundamental and quantitative quantum field theory of a Dislocation has remained undiscovered for decades. Here we present an exactly-solvable one-dimensional quantum field theory of a Dislocation, for both edge and screw Dislocations in an isotropic medium, by introducing a new quasiparticle which we have called the 'dislon'. The electron-Dislocation relaxation time can then be studied directly from the electron self-energy calculation, which is reducible to classical results. In addition, we predict that the electron energy will experience an oscillation pattern near a Dislocation. Compared with the electron density's Friedel oscillation, such an oscillation is intrinsically different since it exists even with only single electron is present. With our approach, the effect of Dislocations on materials' non-mechanical properties can be studied at a full quantum field theoretical level.
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electron energy can oscillate near a Crystal Dislocation
IOP Publishing, 2017Co-Authors: Mingda Li, Mildred S Dresselhaus, Gang ChenAbstract:United States. Department of Energy. Office of Science. Solid-State Solar Thermal Energy Conversion Center (Award DE-SC0001299/DE-FG02-09ER46577)