title: Nuclear spin dynamics in the quantum regime of a single-molecule magnet.
abstract: We show that the nuclear spin dynamics in the single-molecule magnet Mn12-ac below 1 K is governed by quantum tunneling fluctuations of the cluster spins, combined with intercluster nuclear spin diffusion. We also obtain the first experimental proof that-surprisingly-even deep in the quantum regime the nuclear spins remain in good thermal contact with the lattice phonons. We propose a simple model for how T-independent tunneling fluctuations can relax the nuclear polarization to the lattice that may serve as a framework for more sophisticated theories.
authors.affiliation: Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300RA Leiden, The Netherlands. morello@physics.ubc.ca
authors.forename: A
authors.initials: A
authors.lastname: Morello
authors.forename: O N
authors.initials: ON
authors.lastname: Bakharev
authors.forename: H B
authors.initials: HB
authors.lastname: Brom
authors.forename: R
authors.initials: R
authors.lastname: Sessoli
authors.forename: L J
authors.initials: LJ
authors.lastname: de Jongh