Nuclear magnetic resonance for quantum computing: Techniques and recent achievements
Xin Tao1, Wang Bi-Xue1, Li Ke-Ren1, Kong Xiang-Yu1, Wei Shi-Jie1, Wang Tao1, Ruan Dong1, Long Gui-Lu1, 2, 3,
       

(color online) Schematic representation of dynamical decoupling pulse sequences. During the evolution from t=0 to t=T, π pulses are continually applied to the protected state with different time points. Time point of is labeled by the symbol δ i.