The suppression of ferroquadrupolar order in TmVO4 in a magnetic field is well-described by the transverse field Ising model, enabling detailed studies of critical dynamics near the quantum phase transition. We describe nuclear magnetic resonance measurements in pure and Y-doped single crystals. The non-Kramers nature of the ground state doublet leads to a unique form of the hyperfine coupling that exclusively probes the transverse field susceptibility. Our results show that this quantity diverges at the critical field, in contrast to the mean-field prediction. Furthermore, we find evidence for quantum critical fluctuations present near Tm-rich regions in Y-doped crystals at levels beyond which long-range order is suppressed, suggesting the presence of quantum Griffiths phases.
@article{arxiv.2402.18519,
title = {Nuclear magnetic resonance studies in a model transverse field Ising system},
author = {Y-H. Nian and I. Vinograd and C. Chaffey and Y. Li and M. P. Zic and P. Massat and R. R. P. Singh and I. R. Fisher and N. J. Curro},
journal= {arXiv preprint arXiv:2402.18519},
year = {2024}
}