Proximate ferromagnetic state in the Kitaev model material α-RuCl3

Abstract α -RuCl 3 is a major candidate for the realization of Kitaev quantum spin liquid, but its zigzag antiferromagnetic order at low temperatures indicates deviations from model. We have quantified Hamiltonian by resonant inelastic x-ray scattering study Ru L absorption edge. In paramagnetic state, quasi-elastic intensity magnetic excitations has broad maximum around zone center without any local maxima Bragg wavevectors. This finding implies that fragile and readily destabilized competing ferromagnetic correlations. The classical ground state experimentally determined actually ferromagnetic. stabilized fluctuations, leaving ferromagnetism – along with liquid as energetically proximate metastable states. three closely states their collective hold key to theoretical understanding unusual properties in fields.