Stimulated adiabatic passage in a dissipative ensemble of atoms with strong Rydberg-state interactions

We study two-photon excitation of Rydberg states of atoms under stimulated adiabatic passage with delayed laser pulses. We find that the combination of strong interaction between the atoms in Rydberg state and the spontaneous decay of the intermediate exited atomic state leads to the Rydberg excitation of precisely one atom within the atomic ensemble. The quantum Zeno effect offers a lucid interpretation of this result: the Rydberg blocked atoms repetitively scattering photons effectively monitor a randomly excited atom, which therefore remains in the Rydberg state. This system can be used for deterministic creation and, possibly, extraction of Rydberg atoms or ions one at a time. The sympathetic monitoring via decay of ancilla particles may find wider applications for state preparation and probing of interactions in dissipative many-body systems.

Figure 1

(a) Level scheme of atoms interacting with the fields ${\Omega }_{ge}$ and ${\Omega }_{er}$ on the transitions $|g\rangle \to |e\rangle$ and $|e\rangle \to |r\rangle$, while ${\Gamma }_{eg}$ and ${\Gamma }_{re}$ are (population) decay rates of states $|e\rangle$ and $|r\rangle$. ${\mathcal{V}}_{\mathrm{aa}}$ denotes the interaction between atoms in Rydberg state $|r\rangle$. (b) Time dependence of the ${\Omega }_{ge}$ and ${\Omega }_{er}$ fields. (c) The corresponding time-dependent probabilities $P_r\left(n\right)$ of $n=0,1,2$ Rydberg excitations in a compact ensemble of $N=1-6$ atoms, (c1)–(c6), obtained from the exact solutions of Eq. (1); thicker lines correspond to the dissipative system (${\Gamma }_{eg},{\Gamma }_{re}$ given in the text), while thinner lines to the fully coherent dynamics of nondecaying atoms (${\Gamma }_{eg},{\Gamma }_{re}\simeq 0$).

Figure 2

Probabilities $P_r\left(1\right)$ of single Rydberg excitation of superatom composed of $N=1-6$ atoms, obtained from the exact solutions of Eq. (1) including dephasing ${\gamma }_r$ and decays ${\Gamma }_{eg},{\Gamma }_{re}$. Main panel shows the time dependence of $P_r\left(1\right)$, and inset shows $P_r\left(1\right)$ for different $N$ at time $t_{\mathrm{end}}=30\mu$s.