Revealing a Triangular Lattice Ising Antiferromagnet in a Single-Crystal   CeCd$_3$As$_3$
  We report the single-crystal growth and the fundamental magnetic and thermodynamic properties of a rare-earth triangular lattice antiferromagnet CeCd$_3$As$_3$. In this rare-earth antiferromagnet, the Ce local moments form a perfect triangular lattice. Due to the spin-orbital-entangled nature of the Ce local moments, the compound exhibits extremely anisotropic antiferromagnetic couplings along the c direction and in the ab plane respectively. We show that CeCd$_3$As$_3$ represents a {\it rare} experimental realization of an antiferromagnetic Ising model on a two dimensional triangular lattice and thus provides a prototype example for geometrical frustration. We further discuss the quantum effect of the perturbative interactions on the top of the predominant Ising interaction. 
Y. Q. Liu, S. J. Zhang, J. L. Lv, S. K. Su, T. Dong, Gang Chen, N. L.   Wang
cond-mat.str-el