State-independent experimental tests of quantum contextuality in a three   dimensional system
  We experimentally observed state-independent violations of Kochen-Specker inequalities for the simplest indivisible quantum system manifesting quantum contextuality, a three-level (qutrit) system. We performed the experiment with a single trapped ^{171}Yb^{+} ion, by mapping three ground states of the ^{171}Yb^{+} ion to a qutrit system and carrying out quantum operatations by applying microwaves resonant to the qutrit transition frequencies. Our results are free from the detection loophole and cannot be explained by the non-contextual hidden variable models. 
Xiang Zhang, Mark Um, Junhua Zhang, Shuoming An, Ye Wang, Dong-ling   Deng, Chao Shen, Luming Duan, Kihwan Kim
quant-ph