Quantum spin liquids (QSLs) have become a key area of research in magnetism due to their remarkable properties, such as long-range entanglement, fractional excitations, pinch-point singularities, and topologically protected phenomena. In recent years, the search for QSLs has expanded into the three-dimensional world, where promising features have been found in materials that form pyrochlore and hyper-kagome lattices, despite the suppression of quantum fluctuations due to high dimensionality. One such material is the S=1 K2Ni2(SO4)3 compound, which belongs to the langbeinite family consisting of two interconnected trillium lattices. Although magnetically ordered, K2Ni2(SO4)3 has been found to exhibit a highly dynamical and correlated state which can be driven into a pure quantum spin liquid under magnetic fields of only B≃4~T. In this article, we combine inelastic neutron scattering measurements with pseudo-fermion functional renormalization group (PFFRG) and classical Monte Carlo (cMC) calculations to study the magnetic properties of K2Ni2(SO4)3, revealing a high level of agreement between the experiment and theory. We further reveal the origin of the dynamical state in K2Ni2(SO4)3 by studying a larger set of exchange parameters, uncovering an `island of liquidity' around a focal point given by a magnetic network composed of tetrahedra on a trillium lattice.
@article{arxiv.2308.11746,
title = {Dynamics of K$_2$Ni$_2$(SO$_4$)$_3$ governed by proximity to a 3D spin liquid model},
author = {M. G. Gonzalez and V. Noculak and A. Sharma and V. Favre and J-R. Soh and A. Magrez and R. Bewley and H. O. Jeschke and J. Reuther and H. M. Rønnow and Y. Iqbal and I. Živković},
journal= {arXiv preprint arXiv:2308.11746},
year = {2024}
}