Experimental Test of Complementarity by Nuclear Magnetic Resonance Techniques

We have tested complementarity for the ensemble-averaged spin states of nuclei $^{13}$C in the molecule of $^{13}$CHCl$_{3}$ by the use of the spin states of another nuclei $^{1}$H as the path marker. It turns out that the wave-particle duality holds when one merely measures the probability density of quantum states, and that the wave- and particle-like behavior is simultaneously observed with the help of measuring populations and coherence in a single nuclear magnetic resonance(NMR) experiment. Effects of path-marking schemes and causes of the appearance and disappearance of the wave behavior are analysed.