Quantum Impurities and the Neutron Resonance Peak inYBa2Cu3O7: Ni versus Zn
| Autor: | Yvan Sidis, Gaston Collin, Jacques Bossy, P. Gautier-Picard, D. L. Millius, P. Bourges, Bernhard Keimer, Bernard Hennion, L. P. Regnault, H. F. Fong, Alexandre Ivanov, Ilhan A. Aksay |
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| Rok vydání: | 2000 |
| Předmět: |
Physics
High-temperature superconductivity Condensed matter physics Spin dynamics Physics::Medical Physics Neutron resonance General Physics and Astronomy 02 engineering and technology Normal state 021001 nanoscience & nanotechnology 01 natural sciences Lower energy law.invention Crystallography Impurity law 0103 physical sciences 010306 general physics 0210 nano-technology Quantum Spin-½ |
| Zdroj: | Physical Review Letters. 84:5900-5903 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | The influence of magnetic ( $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$) and nonmagnetic ( $S\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$) impurities on the spin dynamics of an optimally doped high temperature superconductor is compared in ${\mathrm{YBa}}_{2}({\mathrm{Cu}}_{0.97}{\mathrm{Ni}}_{0.03}{)}_{3}{\mathrm{O}}_{7}$ ( ${T}_{c}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}80\mathrm{K}$) and ${\mathrm{YBa}}_{2}({\mathrm{Cu}}_{0.99}{\mathrm{Zn}}_{0.01}{)}_{3}{\mathrm{O}}_{7}$ ( ${T}_{c}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}78\mathrm{K}$). In the Ni-substituted system, the magnetic resonance peak (which is observed at ${E}_{r}\ensuremath{\simeq}40\mathrm{meV}$ in the pure system) shifts to lower energy with a preserved ${E}_{r}/{T}_{c}$ ratio while the shift is much smaller upon Zn substitution. By contrast Zn, but not Ni, restores significant spin fluctuations around 40 meV in the normal state. These observations are discussed in the light of models proposed for the magnetic resonance peak. |
| Databáze: | OpenAIRE |
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