Coherent tunneling of lithium defect pairs in KCl crystals

摘要: The tunneling of two lithium ion impurities on next-nearest neighbor sites in potassium chloride are investigated both experimentally and theoretically. strong dipolar interaction leads to coherent motion the defect ions between degenerate off-center positions. Comparing data rotary echo experiments for impurity pairs 7Li—7Li, 6Li—6Li, 7Li—6Li with theory permits a thorough investigation isotope effect tunnel states. Our findings confirm model states be valid even strongly interacting impurities. Using perturbation terms two-particle states, we obtain essentially exact expressions spectrum dynamical susceptibility which agree well measured data.