Anomalous dielectric response in the dimer Mott insulator kappa-(BEDT-TTF)(2)Cu-2(CN)(3)

作者：Abdel Jawad Majed^*; Terasaki Ichiro; Sasaki Takahiko; Yoneyama Naoki; Kobayashi Norio; Uesu Yoshiaki; Hotta Chisa

来源：Physical Review B, 2010, 82(12): 125119.

DOI：10.1103/PhysRevB.82.125119

We have measured and analyzed the dielectric constant of the dimer Mott insulator kappa-(BEDT-TTF)(2)Cu-2(CN)(3), which is known as a playground for a spin-liquid state. Most unexpectedly, this particular organic salt has nontrivial charge degrees of freedom, being characterized by a relaxor-like dielectric relaxation below around 60 K. This is ascribed to the charge disproportionation within the dimer due to the intersite Coulomb repulsion. A possible microscopic model is suggested and discussed.

• 出版日期2010-9-21