2009 年 78 巻 12 号 p. 123704
The 63Cu nuclear quadrupole resonance (NQR) frequency νQ in the multilayered cuprates is calculated in the cluster model by the exact diagonalization method. The charge imbalance between the outer CuO2 plane (OP) with apical oxygen OA and the inner plane (IP) without OA in three-layered Tl2Ba2Ca2Cu3O10 is estimated by comparing our results with the experimental νQ. In Tl-based cuprates with more than three layers, we predict a large enhancement of the splitting of νQ between OP and IP by taking into account the reduction in bond length between Cu and OA and the resulting increase in charge transfer energy. Our results show that the NQR frequency is a useful quantity for estimating the charge imbalance in the multilayered cuprates.