Multiatom Greenberger-Horne-Zeilinger states using cavity-induced Rydberg blockade

TL;DR

This paper introduces a new method to generate multiatom GHZ states using cavity-induced Rydberg blockade, enabling entanglement over millimeter distances with low dissipation.

Contribution

It presents a novel scheme for creating GHZ states in cold atoms via cavity-mediated virtual photon exchange causing asymmetric Rydberg blockade.

Findings

Successful suppression of simultaneous Rydberg excitations.

Entanglement generation over millimeter-scale distances.

Adiabatic transfer into entangled states with low dissipation.

Abstract

We describe a novel method for producing Greenberger-Horne-Zeilinger states in cold atoms coupled to a superconducting coplanar cavity. In the proposed scheme, atoms interact between each other by virtual photon exchange via a cavity mode. These interactions cause an asymmetric Rydberg blockade mechanism that suppresses simultaneous excitations into different atomic Rydberg levels, thus forcing all atoms to occupy the same Rydberg state. This mechanism has effect even if the atoms are separated by distances of the order of millimeters. The atomic populations are transferred adiabatically from the ground state into the entangled state by following a collective dark state with low dissipation rates.