Nic Shannon (Oxford and OIST)
Nematic phases, in which molecules align to break rotational symmetries of space - without at the same time breaking translational symmetries - are ubiquitous in nature. It has long been a subject of discussion whether a quantum magnet could also achieve this type of order. However identifying a quantum spin-nematic in a real material presents a number of challenges. Firstly, magnetic moments transform as vectors, not directors, and so mean field interactions inevitably favour more conventional forms of magnetic order. Secondly, the widely used probes of magnetic order, including neutron scattering, NMR and \muSR, couple to internal magnetic fields in the sample. Since quantum spin nematics do not break time reversal symmetry, such internal fields must vanish, and rendering spin-nematic order "invisible". Here we propose a stratgey for stabilizing quantum spin nematic phases based on frustrated ferromagnetic interactions, low dimension and high magnetic field . LiCuVO4 is singled out as a material which meets all of these requirements, and where a potential spin-nematic phase has been identified near saturation [2,3]. We further show how the temperature dependence of NMR T1 relaxation rates could be used to distinguish a quantum spin-nematic in LiCuVO4.