Microscopic Properties of the Pinwheel Kagome Compound Rb2Cu3SnF12

作者：Grbic M S^*; Kraemer S; Berthier C; Trousselet F; Cepas O; Tanaka H; Horvatic M

来源：Physical Review Letters, 2013, 110(24): 247203.

DOI：10.1103/PhysRevLett.110.247203

Using Cu-63,Cu-65 nuclear magnetic resonance in magnetic fields up to 30 T, we study the microscopic properties of the 12-site valence-bond-solid ground state in the %26quot;pinwheel%26quot; kagome compound Rb2Cu3SnF12. We find that the ground state is characterized by a strong transverse staggered spin polarization whose temperature and field dependence points to a mixing of the singlet and triplet states. This is further corroborated by the field dependence of the gap Delta(H), which has a level anticrossing with a large minimum gap value of approximate to Delta(0)/2, with no evidence of a phase transition down to 1.5 K. By the exact diagonalization of small clusters, we show that the observed anticrossing is mainly due to staggered tilts of the g tensors defined by the crystal structure and reveal symmetry properties of the low-energy excitation spectrum compatible with the absence of level crossing.

• 出版日期2013-6-12