NMR Relaxation and Resistivity from Rattling Phonons in Pyrochlore Superconductors

Theoretical study of NMR relaxation due to rattling phonons

We calculate the NMR relaxation rate due to quadrupolar coupling of the nucleus to a local, strongly anharmonic phonon mode. As a model potential for a “rattling” motion we consider a square-well potential. We calculate the free phonon Green’s function analytically and derive the low and high temperature limits of the NMR relaxation rate. It is shown that the temperature dependence of the NMR r...

NMR relaxation and rattling phonons in the type-I Ba8Ga16Sn30 clathrate

Atomic motion of guest atoms inside semiconducting clathrate cages is considered an important source for glasslike thermal behavior. 69Ga and 71Ga nuclear magnetic resonance studies on type I Ba8Ga16Sn30 show a clear low-temperature relaxation peak attributed to the influence of Ba rattling dynamics on the framework-atom resonance, with a quadrupolar relaxation mechanism as the leading contribu...

Effects of Rattling Phonons on the Dynamics of Quasiparticle Excitation in the -Pyrochlore KOs2O6 Superconductor

Protein dynamics: from rattling in a cage to structural relaxation.

We present an overview of protein dynamics based mostly on results of neutron scattering, dielectric relaxation spectroscopy and molecular dynamics simulations. We identify several major classes of protein motions on the time scale from faster than picoseconds to several microseconds, and discuss the coupling of these processes to solvent dynamics. Our analysis suggests that the microsecond bac...

Novel rattling of K atoms in aluminium-doped defect pyrochlore tungstate.

Rattling dynamics have been identified as fundamental to superconductivity in defect pyrochlore osmates and aluminium vanadium intermetallics, as well as low thermal conductivity in clathrates and filled skutterudites. Combining inelastic neutron scattering (INS) measurements and ab initio molecular dynamics (MD) simulations, we use a new approach to investigate rattling in the Al-doped defect ...