Graph (IMAGE) Moscow Institute of Physics and Technology Caption The graph above shows the results of the experiment: Wave frequencies are plotted on the horizontal axis against radiation intensity on the vertical axis. The two highest peaks correspond to source radiation frequencies. The peaks labeled in pink, orange, and purple are attributed to the phenomenon of quantum wave mixing on a single atom. The top graph illustrates the experiment using an artificial atom with two energy levels, while the bottom graph corresponds to the case with three energy levels. Credit MIPT Press Office Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.