Perturbation on hyperfine-enhanced Pr nuclear spin dynamics associated with antiferroquadrupolar order in PrVAl

Ito, Takashi   ; Higemoto, Wataru  ; Sakai, Akito*; Nakatsuji, Satoru*; Tsujimoto, Masaki*

The nature of multipolar order and hyperfine-enhanced (HE) Pr nuclear spin dynamics in PrVAl was investigated using the muon spin relaxation technique. No explicit sign of time-reversal symmetry breaking was found below the multipolar order temperature K in a zero applied field as anticipated on the basis of the antiferroquadrupolar (AFQ) order picture proposed by Sakai and Nakatsuji [J. Phys. Soc. Jpn. , 063701 (2011)]. Further evidence of the nonmagnetic ground state was obtained from the observation of HE Pr nuclear spin fluctuations in the MHz scale. A marked increase in the muon spin-lattice relaxation rate (1/) was observed below 1K with decreasing temperature, which was attributed to the perturbation on the HE Pr nuclear spin dynamics associated with the development of AFQ correlations.