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pro vyhledávání: '"Harrison, Walter"'
Autor:
Harrison, Walter A.
It has been shown that the traditional matching of wavefunctions between regions of different effective mass (matching {\psi} and (1/m*)\partial{\psi}/\partialx) is not correct, but that one should match (1/\surdm*){\psi} and (1/\surdm*)\partial{\psi
Externí odkaz:
http://arxiv.org/abs/1108.1224
Autor:
Harrison, Walter A.
A uniform distribution of La and Sr in lanthanum-strontium manganites would lead to charged crystal planes, a charged surface, and arbitrarily large surface energy for a bulk crystal. This divergent energy can be eliminated by depleting the La concen
Externí odkaz:
http://arxiv.org/abs/1101.5414
Autor:
Harrison, Walter A.
A localized description, rather than energy bands, is appropriate for the manganite substrate. Empty substrate levels lower in energy than occupied oxygen levels indicate need for further terms beyond the Local Density Approximation. So also does van
Externí odkaz:
http://arxiv.org/abs/0911.2268
Autor:
Harrison, Walter A.
An earlier analysis of manganese oxides in various charge states indicated that free-atom term values and universal coupling gave a reasonable account of the cohesion. This approach is here extended to LaxSr(1-x)MnO3 in a perovskite structure, and a
Externí odkaz:
http://arxiv.org/abs/0807.2248
Autor:
Harrison, Walter A.
The electronic structure is found to be understandable in terms of free-atom term values and universal interorbital coupling parameters, since self-consistent tight-binding calculations indicate that Coulomb shifts of the d-state energies are small.
Externí odkaz:
http://arxiv.org/abs/0803.0994
Autor:
Harrison, Walter A.
The superexchange intertacion in transition-metal oxides, proposed initially by Anderson in 1950, is treated using contemporary tight-binding theory and existing parameters. We find also a direct exchange for nearest-neighbor metal ions, larger by a
Externí odkaz:
http://arxiv.org/abs/cond-mat/0701423