Effective Hamiltonian for potassium dynamics in theβ-pyrochlore superconductor KOs2O6
| Autor: | W. E. Pickett, J. Kuneš |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Condensed matter physics
Chemistry Anharmonicity Pyrochlore Ab initio Surfaces and Interfaces engineering.material Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials symbols.namesake Lattice (order) Materials Chemistry engineering Coulomb symbols Electrical and Electronic Engineering Hamiltonian (quantum mechanics) Wave function Eigenvalues and eigenvectors |
| Zdroj: | physica status solidi (a). 203:2962-2967 |
| ISSN: | 1862-6319 1862-6300 |
| DOI: | 10.1002/pssa.200567138 |
| Popis: | Based on ab initio energies and forces we construct an effective Hamiltonian for anharmonic dynamics of potassium cations in the /?-pyrochlore compound KOs 2 O 6 . We solve numerically the single-site problem which is characterized by an extremely flat potential well allowing for large excursions of K-ions, and illustrate graphically the K-ion wavefunctions in the four off-center (symmetry-breaking) sites. These large displacements from the ideal lattice site result in sizable K-K near-neighbor interactions through a screened Coulomb interaction. The matrix elements of the interaction in the basis of single-site eigenstates are calculated and discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text