Magnetization, magnetocaloric, calorimetric, neutron and X-ray diffraction and inelastic neutron scattering measurements are performed on single crystals of BaCdVO(PO4)2. The low-temperature crystal structure is found to be of a lower symmetry than previously assumed. The result is a more complicated model spin Hamiltonian, which we infer from measurements of the spin wave dispersion spectrum. The main finding is a novel spin state which emerges in high magnetic fields after antiferromagnetic order is terminated at Hc1≃4.0 T. It is a distinct thermodynamic phase with a well-defined phase boundary at Hc2≃6.5 T and is clearly separate from the fully saturated phase. Yet, it shows no conventional (dipolar) magnetic long range order. We argue that it is fully consistent with the expectations for a quantum bond-nematic state.
@article{arxiv.1908.01734,
title = {Presaturation phase with no dipolar order in a quantum ferro-antiferromagnet},
author = {V. K. Bhartiya and K. Yu. Povarov and D. Blosser and S. Bettler and Z. Yan and S. Gvasaliya and S. Raymond and E. Ressouche and K. Beauvois and J. Xu and F. Yokaichiya and A. Zheludev},
journal= {arXiv preprint arXiv:1908.01734},
year = {2019}
}