NMR Observation of Rattling Phonons in the Pyrochlore Superconductor KOs_2O_6

@article{citeulike:2874745, abstract = {We report nuclear magnetic resonance studies on the beta-pyrochlore oxide superconductor KOs<SUB>2</SUB>O<SUB>6</SUB>. The nuclear relaxation at the K sites is entirely caused by fluctuations of the electric field gradient, which we ascribe to highly anharmonic low frequency oscillation (rattling) of K ions. A phenomenological analysis shows a crossover from overdamped to underdamped behavior of the rattling phonons with decreasing temperature and its sudden sharpening below the superconducting transition temperature T<SUB>c</SUB>. Suppression of the Hebel-Slichter peak in the relaxation rate at the O sites below T<SUB>c</SUB> also indicates strong electron-phonon coupling.}, author = {Yoshida, M. and Arai, K. and Kaido, R. and Takigawa, M. and Yonezawa, S. and Muraoka, Y. and Hiroi, Z. }, citeulike-article-id = {2874745}, doi = {10.1103/PhysRevLett.98.197002}, eprint = {cond-mat/0610760}, eprint = {cond-mat/0610760}, journal = {Physical Review Letters}, keywords = {experiment, kos2o6, nmr, pyrochlore, rattling}, month = {May}, number = {19}, pages = {197002+}, posted-at = {2008-06-09 08:17:58}, priority = {0}, title = {NMR Observation of Rattling Phonons in the Pyrochlore Superconductor KOs\_{2O\_{6}}}, url = {http://arxiv.org/abs/cond-mat/0610760}, volume = {98}, year = {2007} }

TY - JOUR ID - citeulike:2874745 L3 - citeulike-article-id:2874745 TI - NMR Observation of Rattling Phonons in the Pyrochlore Superconductor KOs_{2O_{6}} JF - Physical Review Letters VL - 98 IS - 19 SP - 197002 N2 - We report nuclear magnetic resonance studies on the beta-pyrochlore oxide superconductor KOs<SUB>2</SUB>O<SUB>6</SUB>. The nuclear relaxation at the K sites is entirely caused by fluctuations of the electric field gradient, which we ascribe to highly anharmonic low frequency oscillation (rattling) of K ions. A phenomenological analysis shows a crossover from overdamped to underdamped behavior of the rattling phonons with decreasing temperature and its sudden sharpening below the superconducting transition temperature T<SUB>c</SUB>. Suppression of the Hebel-Slichter peak in the relaxation rate at the O sites below T<SUB>c</SUB> also indicates strong electron-phonon coupling. KW - experiment KW - kos2o6 KW - nmr KW - pyrochlore KW - rattling AU - Yoshida, M AU - Arai, K AU - Kaido, R AU - Takigawa, M AU - Yonezawa, S AU - Muraoka, Y AU - Hiroi, Z PY - 2007/May// UR - http://arxiv.org/abs/cond-mat/0610760 ER -