Emergence of the Isotropic Kitaev Honeycomb Lattice with Two-dimensional   Ising Universality in {\alpha}-RuCl$_3$
  Anderson proposed structural topology in frustrated magnets hosting novel quantum spin liquids (QSLs). The QSL state is indeed exactly derived by fractionalizing the spin excitation into spinless Majorana fermions in a perfect two dimensional (2D) honeycomb lattice, the so-called Kitaev lattice, and its experimental realisation is eagerly being pursued. Here we, for the first time, report the Kitaev lattice stacking with van der Waals (vdW) bonding in a high quality {\alpha}-RuCl$_3$ crystal using x-ray and neutron diffractions. Even in absence of apparent monoclinic distortion, the system exhibits antiferromagnetic (AFM) ordering below 6.5 K, likely due to minute magnetic interaction from trigonal distortion and/or interlayer coupling additionally to the Kitaev Hamiltonian. We also demonstrate 2D Ising-like critical behaviors near the N\'eel temperature in the order parameter and specific heat, capturing the characteristics of short-range spin-spin correlations underlying the Kitaev model. Our findings hold promise for unveiling enigmatic physics emerging from the Kitaev QSL. 
S.-Y. Park, S.-H. Do, K.-Y. Choi, D. Jang, T.-H. Jang, J. Schefer,   C.-M. Wu, J. S. Gardner, J. M. S. Park, J.-H. Park, Sun...
cond-mat.mtrl-sci