The Experts below are selected from a list of 198 Experts worldwide ranked by ideXlab platform
Mario Rabinowitz - One of the best experts on this subject based on the ideXlab platform.
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Phenomenological Theory of cuprate superconductivity
arXiv: Superconductivity, 2003Co-Authors: Mario Rabinowitz, T. McmullenbAbstract:Reasonably good agreement with the superconducting transition temperatures of the cuprate high-Tc superconductors can be obtained on the basis of an approximate Phenomenological Theory. In this Theory, two criteria are used to calculate the superconducting transition temperature. One is that the quantum wavelength is of the order of the electron-pair spacing. The other is that a very small fraction of the normal carriers exist as Cooper pairs at Tc. The resulting simple equation for Tc contains only two parameters: the normal carrier density and effective mass. We calculate specific transition temperatures for twelve cuprate superconductors.
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Phenomenological Theory of superfluidity and superconductivity
International Journal of Theoretical Physics, 1994Co-Authors: Mario RabinowitzAbstract:Quantum condensation is used here as the basis for a Phenomenological Theory of superfluidity and superconductivity. It leads to remarkably good calculations of the transition temperaturesT c of superfluid3He and4He, as well as a large number of cuprate, heavy fermion, organic, dichalcogenide, and bismuth oxide superconductors. Although this approach may apply least to the long-coherence-length metallics, reasonably good estimates are made for them and chevral superconductors.T c for atomic H is estimated.T c can be calculated as a function of number density or density of states and effective mass of normal carriers; or alternatively with the Fermi energy as the only input parameter. Predictions are made for a total of 26 superconductors and four superfluids. An estimate is also made for coherence lengths.
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Phenomenological Theory of cuprate superconductivity
Applied Physics Letters, 1993Co-Authors: Mario Rabinowitz, T. McmullenAbstract:Reasonably good agreement with the superconducting transition temperatures of the cuprate high‐Tc superconductors can be obtained on the basis of an approximate Phenomenological Theory. In this Theory, two criteria are used to calculate the superconducting transition temperature. One is that the quantum wavelength is of the order of the electron‐pair spacing. The other is that a fraction of the normal carriers exist as Cooper pairs at Tc. The resulting simple equation for Tc contains only two parameters: the normal carrier density and effective mass. We calculate specific transition temperatures for 12 cuprate superconductors.
M. Fähnle - One of the best experts on this subject based on the ideXlab platform.
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transition matrix elements for electron phonon scattering Phenomenological Theory and ab initio electron Theory
Physical Review B, 2015Co-Authors: Christian Illg, Michael Haag, B Y Mueller, G Czycholl, M. FähnleAbstract:Transition matrix elements for electron-phonon scattering are discussed. The approximate expression for the matrix element derived by the combination of a Phenomenological Theory of electronic and ionic screening of the electron-electron interaction with a microscopic perturbation Theory for the matrix element is compared with unscreened matrix elements from the ab initio electron Theory. The matrix elements calculated in these two ways differ very strongly. A situation is investigated (ultrafast demagnetization of a ferromagnetic film after excitation with a femtosecond laser pulse) in which nevertheless both types of matrix elements yield similar results for the demagnetization rate.
Vladimir A. Stephanovich - One of the best experts on this subject based on the ideXlab platform.
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Phenomenological Theory of Bloch point relaxation
Journal of Magnetism and Magnetic Materials, 1993Co-Authors: E. G. Galkina, B.a. Ivanov, Vladimir A. StephanovichAbstract:Abstract In the framework of a generalized magnetic relaxation Phenomenological Theory, which includes the exchange relaxational term, the Bloch point (BP) dissipative dynamics was investigated. It was shown, that consideration of exchange relaxation can explain the extremely small BP mobility value, observed in the experiment, contrary to conventional relaxation Theory, based on relativistic terms.
Pinaki Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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turbulent friction in rough pipes and the energy spectrum of the Phenomenological Theory
Physical Review Letters, 2006Co-Authors: Gustavo Gioia, Pinaki ChakrabortyAbstract:The classical experiments on turbulent friction in rough pipes were performed by Nikuradse in the 1930s. Seventy years later, they continue to defy Theory. Here we model Nikuradse's experiments using the Phenomenological Theory of Kolmog\'orov, a Theory that is widely thought to be applicable only to highly idealized flows. Our results include both the empirical scalings of Blasius and Strickler and are otherwise in minute qualitative agreement with the experiments; they suggest that the Phenomenological Theory may be relevant to other flows of practical interest; and they unveil the existence of close ties between two milestones of experimental and theoretical turbulence.
Christian Illg - One of the best experts on this subject based on the ideXlab platform.
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transition matrix elements for electron phonon scattering Phenomenological Theory and ab initio electron Theory
Physical Review B, 2015Co-Authors: Christian Illg, Michael Haag, B Y Mueller, G Czycholl, M. FähnleAbstract:Transition matrix elements for electron-phonon scattering are discussed. The approximate expression for the matrix element derived by the combination of a Phenomenological Theory of electronic and ionic screening of the electron-electron interaction with a microscopic perturbation Theory for the matrix element is compared with unscreened matrix elements from the ab initio electron Theory. The matrix elements calculated in these two ways differ very strongly. A situation is investigated (ultrafast demagnetization of a ferromagnetic film after excitation with a femtosecond laser pulse) in which nevertheless both types of matrix elements yield similar results for the demagnetization rate.
