We study the correlated evolutions of two Rydberg atoms, interacting via a van der Waals (vdW) potential $V_6$ and driven by a laser field of detunings ${\mathrm{\Delta }}_1$ and ${\mathrm{\Delta }}_2$. The two atoms may exhibit the in-phase dynamics with identical Rydberg populations or the antiphase dynamics with complementary Rydberg populations, depending on their initial states. For a moderate vdW potential far from the blockade regime, the in-phase or antiphase dynamics can be attained along two intersecting lines in the parameter space of ${\mathrm{\Delta }}_1$ and ${\mathrm{\Delta }}_2$ with an exact or approximate figure of merit, respectively. Note, in particular, that the exact in-phase dynamics is trivial because it requires identical detunings while the approximate in-phase, exact antiphase, and approximate antiphase dynamics are nontrivial because they require distinct detunings. The specific requirements on ${\mathrm{\Delta }}_1$ and ${\mathrm{\Delta }}_2$ for both in-phase and antiphase dynamics can be understood by considering the balanced transitions from two initially populated states to two initially empty states in the double-atom state basis.

• Received 18 November 2018

DOI:https://doi.org/10.1103/PhysRevA.99.033813