Anisotropic magnetic fluctuations in YbRh$_2$ Si$_2$

S. Kambe (1) , S. Sakai (1) , Y. Tokunaga (1) , G. Lapertot (2) , T Matsuda (3) , G. Knebel (2) , J. Flouquet (2) , R Walstedt (4)

1 JAEA - Japan Atomic Energy Agency [Ibaraki]
2 IMAPEC - Instrumentation, Material and Correlated Electrons Physics
3 TMU - Tokyo Metropolitan University [Tokyo]
4 University of Michigan [Ann Arbor]

$^{29}$Si nuclear magnetic resonance (NMR) has been measured in a $^{29}$Si enriched single crystal sample of YbRh$_2$Si$_2$. The spin-lattice relaxation rate 1/T$_1$ for applied field $H$ || the c-axis is considerably different from that for $H$ ⊥ the c-axis, reflecting the tetragonal symmetry of the compound. At low temperatures, in-plane magnetic fluctuations deduced from these 1/T$_1$ results are found to depend strongly on the direction of $H$, i.e. the in-plane magnetic fluctuations are suppressed for $H$ ⊥ the c-axis compared to the case for $H$ || the c-axis, indicating that the electronic state is sensitive to the direction of $H$ at low temperatures.

Domaines: Matière Condensée [cond-mat]; Supraconductivité [cond-mat.supr-con]; Electrons fortement corrélés [cond-mat.str-el]

S. Kambe, S. Sakai, Y. Tokunaga, G. Lapertot, T Matsuda, et al.. Anisotropic magnetic fluctuations in YbRh$_2$ Si$_2$. Journal of Physics: Conference Series, 2015, 592, pp.012085. ⟨10.1088/1742-6596/592/1/012085⟩. ⟨hal-02064917⟩