Observation of the stark-tuned Förster resonance between two Rydberg atoms

Phys Rev Lett. 2010 Feb 19;104(7):073003. doi: 10.1103/PhysRevLett.104.073003. Epub 2010 Feb 18.

Abstract

Cold atoms in highly excited Rydberg states are promising candidates to implement quantum logic gates of a quantum computer via long-range dipole-dipole interaction. Two-qubit gates require a controlled interaction of only two close Rydberg atoms. We report on the first spectroscopic observation of the resonant dipole-dipole interaction between two cold rubidium Rydberg atoms confined in a small laser excitation volume. The interaction strength was controlled by fine-tuning of the Rydberg levels into a Förster resonance using the Stark effect. The observed resonance line shapes are in good agreement with numerical Monte Carlo simulations.