Dynamical Entanglement of Vibrations in Integrable Dimer and Small Molecules

By means of the reduced-density linear entropy, we investigate the properties of dynamical entanglement of vibrations in integrable dimer and realistic small molecules which are initially in the two-mode squeezed vacuum state. It is found that the entropy of the integrable dimer is periodic for weak coupling strength cl and small squeezing parameter r, and there exists a beat phenomenon for strong el and large r. Moreover, the entropy of the small molecules is quasi-periodic for small r, ＆nd the begt phenomenon occurs in the entropy evolution of the two molecules C2D2 and S02 for large r. Our results might be used for molecular quantum computing based on vibrational states.