Rydberg Atom Entanglements in the Weak Coupling Regime

Abstract

We present an entanglement scheme for Rydberg atoms using the van der Waals interaction phase induced by Ramsey-type pulsed interactions. This scheme realizes not only controlled phase operations between atoms at a distance larger than Rydberg blockade distance, but also various counterintuitive entanglement examples, including two-atom entanglement in the presence of a closer third atom and W-state generation for three partially blockaded atoms. Experimental realization is conducted with single rubidium atoms in optical tweezer dipole traps, to demonstrate the proposed entanglement generations with an entanglement fidelity of F = 0.59 +/- 0.11.