- Autor(in)
- Sponsor(in)
- Referenz
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- Seitenbereich
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0263 - 0286
- Schlagwort(e)
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<KWD>Tunneling states
Isotope effect
Rotary echoes
- Zusammenfsg.
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The tunneling of two lithium ion impurities on next-nearest neighbor sites in potassium chloride are investigated both experimentally and theoretically. The strong dipolar interaction leads to coherent tunneling motion of the two defect ions between degenerate off-center positions. Comparing data of rotary echo experiments for impurity pairs <sup>7</sup>Li - <sup>7</sup>Li, <sup>6</sup>Li - <sup>6</sup>Li, and <sup>7</sup>Li - <sup>6</sup>Li with theory permits a thorough investigation of the isotope effect and of the effect of the interaction on the tunnel states. Our findings confirm the tunneling model with <111> off-center states to be valid even for strongly interacting impurities. Using degenerate perturbation theory in terms of two-particle states, we obtain essentially exact expressions for the tunneling spectrum and the dynamical susceptibility which agree well with the measured data.
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- Forschungsartikel