Exotic quantum liquid state on new kagome antiferromagnets

采用磁学测量和中子散射实验研究了新型S=1/2 kagome反铁磁体Rb_2Cu_3SnF_<12>和Cs_2Cu_3SnF_<12>的基态和磁激发谱。对于Rb_2Cu_3SnF_<12>，基态为非磁性，自旋态为“风车”键固态。另一方面，对于Cs_2Cu_3SnF_<12>，在Neel温度T_N=20K下实现了q=0的自旋结构。详细的自旋结构和自旋波的色散正在进行中。

The ground states and the magnetic excitation spectra were investigated by means of the magnetic measurements and the neutron scattering experiments for new S=1/2 kagome antiferromagnets Rb_2Cu_3SnF_<12> and Cs_2Cu_3SnF_<12>. For Rb_2Cu_3SnF_<12>, the ground state is non-magnetic, and the spin state is described by "pinwheel" valence-bond-solid state. On the other hand, for Cs_2Cu_3SnF_<12>, q=0 spin structure is realized below Neel temperature T_N=20K. Detailed spin structure and the dispersion of the spin waves are under way.