Quantum spin liquid in frustrated one dimensional LiCuSbO4
  A quantum magnet, LiCuSbO4, with chains of edge-sharing S = 1/2 CuO6 octahedra is reported. While the Curie-Weiss constant is ferromagnetic, \theta = 30 K, no phase transition or spin freezing occurs down to 100 mK. Specific heat indicates a distinct high field phase near the 12 T saturation field. Neutron scattering shows incommensurate spin correlations with q = 0.47\pm0.01{\pi}/a and places an upper limit of 70 \mueV on a potential spin gap. Exact diagonalization of easy plane S = 1/2 chains with competing ferro- and antiferromagnetic interactions (J1 = - 75 K, J2 = 34 K) accounts for the T > 2 K data. 
S. E. Dutton, M. Kumar, M. Mourigal, Z. G. Soos, J.-J. Wen, C. L.   Broholm, N. H. Andersen, Q. Huang, M. Zbiri, R. Toft-Pet...
cond-mat.str-el