Nuclear Quadrupole Resonance in the Charge Density Wave State of 1T-TaS₂

Abstract

The ¹⁸¹Ta nuclear quadrupole resonance (NQR) study of 1T-TaS₂ has been made at 4.2 K in the frequency range from 75 MHz to 235 MHz in order to obtain detailed information on the superlattice structure in the commensurate charge density wave state. NQR signals from inequivalent Ta sites are divided into three groups, whose quadrupole frequencies and asymmetry parameters are definitely different from one another. These results are understood on the basis of the star-shaped cluster model including the effect of three-dimensional (3D) ordering of the CDW.