QUROPE Quantum Information Processing and Communication in Europe

A. Browaeys (P2b CNRS), seminar, Entanglement of two individual atoms using the Rydberg blockade

A, Browaeys (P2b), seminar, Entanglement of two individual atoms using the Rydberg blockade

A. Browaeys (P2b CNRS), seminar, Entanglement of two individual atoms using the Rydberg blockade

A. Browaeys (P2b CNRS), seminar, Intrication de deuy atomes par blocage de Rydberg 

A. Browaeys (P2b CNRS), seminar, Entanglement of two individual atoms using the Rydberg blockade

C. Evellin (P2b CNRS), presentation, Intrication de deux atomes par le blocage de Rydberg

A. Browaeys (P2b CNRS), invited talk, Entanglement of two individual atoms using the Rydberg blocade

We report the generation of entanglement between two individual $^{87}$Rb atoms in hyperfine ground states $|F=1,M=1>$ and $|F=2,M=2>$ which are held in two optical tweezers separated by 4 $\mu$m. Our scheme relies on the Rydberg blockade effect which prevents the simultaneous excitation of the two atoms to a Rydberg state. The entangled state is generated in about 200 ns using pulsed two-photon excitation. We quantify the entanglement by applying global Raman rotations on both atoms.

Making use of the Rydberg blockade, we generate entanglement between two atoms individually trapped in two optical tweezers. In this paper we detail the analysis of the data and show that we can determine the amount of entanglement between the atoms in the presence of atom losses during the entangling sequence. Our model takes into account states outside the qubit basis and allows us to perform a partial reconstruction of the density matrix describing the two atom state.

We propose an engineered reservoir inducing the relaxation of a cavity field towards non-classical states. It is made up of two-level atoms crossing the cavity one at a time. Each atom-cavity interaction is first dispersive, then resonant, then dispersive again. The reservoir pointer states are those produced by a fictitious Kerr Hamiltonian acting on a coherent field. We thereby stabilize squeezed states and quantum superpositions of multiple coherent components in a cavity having a finite damping time.