Loss of Ultracold Rb87Cs133 Molecules via Optical Excitation of Long-Lived Two-Body Collision …

We show that the lifetime of ultracold ground-state Rb87Cs133 molecules in an optical trap is limited by fast optical excitation of long-lived two-body collision complexes. We partially suppress this loss mechanism by applying square-wave modulation to the trap intensity, such that the molecules spend 75% of each modulation cycle in the dark. By varying the modulation frequency, we show that the lifetime of the collision complex is 0.53±0.06 ms...