Spin Dynamics And Quadrupole Fluctuations In The Rare-Earth Vanadates YbVO4 And TmVO4*

Nematic fluctuations in a number of correlated quantum materials are intricately linked to their physical properties and quantum phase transitions. Here, we propose that a group of rare-earth vanadates (RVO₄) can be used to capture multipole-lattice dynamics associated with the localized nematic order of the 4f degree of freedom. As an illustrative example, we present an experimental study of the dynamical susceptibilities of YbVO₄ and TmVO₄, with Kramers’ and non-Kramers’ doublet crystal field ground states, respectively. We will discuss the thermal modeling of the dynamic susceptibility, as well as the implications of the observed slow dynamics in the context of a potential “nematic glass” phase.