Quantum criticality in a uranium heavy fermion system revealed with NMR spin-spin relaxation

Kambe, Shinsaku  ; Sakai, Hironori   ; Tokunaga, Yo  ; Matsuda, Tatsuma; Haga, Yoshinori   ; Yasuoka, Hiroshi; Chudo, Hiroyuki ; Walstedt, R. E.*

In order to clarify quantum criticality in heavy fermion systems, we propose to use the Gaussian spin-echo decay rate of the NMR spin-spin relaxation. In contrast to the spin-lattice relaxation rate , which is connected with the dynamical susceptibility Im, is driven by the static susceptibility Re at finite for an antiferromagnet. The combined quantity is found to provide key information in determining the nature of quantum criticality. The -dependence of for the Sn site in the heavy fermion compound USn is presented as an example.