title: Crossover from the quantum critical to overdamped regime in the heavy-fermion system USn3.
abstract: We report measurements of the 119Sn nuclear spin-echo decay rate 1/T2G in the heavy-fermion compound USn3. From 1/T2G, the magnetic spin-spin correlation length xi is found to vary as xi approximately T(-3/4) above approximately 100 K, which is expected for a quantum critical regime at high temperatures. Combined with the spin-lattice relaxation rate 1/T1, T1T/T2G2 is found to be temperature independent in the heavy-fermion state below T* approximately 30 K. This indicates that the heavy-fermion state of USn3 is categorized in the overdamped regime with a dynamical critical exponent z=2. These observations are consistent with a spin density wave magnetic instability at the quantum critical point.
authors.affiliation: Advanced Science Research Center, Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kambe
authors.forename: H
authors.initials: H
authors.lastname: Sakai
authors.forename: Y
authors.initials: Y
authors.lastname: Tokunaga
authors.forename: T D
authors.initials: TD
authors.lastname: Matsuda
authors.forename: Y
authors.initials: Y
authors.lastname: Haga
authors.forename: H
authors.initials: H
authors.lastname: Chudo
authors.forename: R E
authors.initials: RE
authors.lastname: Walstedt