Effect of covalent bonding on magnetism and the missing neutron intensity in copper oxide compounds | |
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學年 | 98 |
學期 | 1 |
出版(發表)日期 | 2009-10-04 |
作品名稱 | Effect of covalent bonding on magnetism and the missing neutron intensity in copper oxide compounds |
作品名稱(其他語言) | |
著者 | Andrew C. Walters, Toby G. Perring, Jean-Sébastien Caux, Andrei T. Savici, Genda D. Gu, Chi-Cheng Lee, Wei Ku, and Igor A. Zaliznyak |
單位 | |
出版者 | |
著錄名稱、卷期、頁數 | Nature Physics 5, p.867-872 |
摘要 | Theories involving highly energetic spin fluctuations are among the leading contenders for explaining high-temperature superconductivity in the cuprates1. These theories could be tested by inelastic neutron scattering (INS), as a change in the magnetic scattering intensity that marks the entry into the superconducting state provides a precise quantitative measure of the spin-interaction energy involved in the superconductivity2,3,4,5,6,7,8,9,10,11. However, the absolute intensities of spin fluctuations measured in neutron scattering experiments vary widely, and are usually much smaller than expected from fundamental sum rules, resulting in ‘missing’ INS intensity2,3,4,5,12,13. Here, we solve this problem by studying magnetic excitations in the one-dimensional related compound, Sr2CuO3, for which an exact theory of the dynamical spin response has recently been developed. In this case, the missing INS intensity can be unambiguously identified and associated with the strongly covalent nature of magnetic orbitals. We find that whereas the energies of spin excitations in Sr2CuO3 are well described by the nearest-neighbour spin-1/2 Heisenberg Hamiltonian, the corresponding magnetic INS intensities are modified markedly by the strong 2p–3d hybridization of Cu and O states. Hence, the ionic picture of magnetism, where spins reside on the atomic-like 3d orbitals of Cu2+ ions, fails markedly in the cuprates. |
關鍵字 | |
語言 | en |
ISSN | |
期刊性質 | 國外 |
收錄於 | SCI |
產學合作 | |
通訊作者 | |
審稿制度 | 是 |
國別 | GBR |
公開徵稿 | |
出版型式 | ,電子版 |
相關連結 |
機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/117385 ) |