Photon-Mediated Quantum Gate between Two Neutral Atoms in an Optical Cavity

Quantum logic gates are fundamental building blocks of quantum computers. Their integration into quantum networks requires strong qubit coupling to network channels, as can be realized with neutral atoms and optical photons in cavity quantum electrodynamics. Here we demonstrate that the long-range i...

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Bibliographic Details
Main Authors: Stephan Welte, Bastian Hacker, Severin Daiss, Stephan Ritter, Gerhard Rempe
Format: Article
Language:English
Published: American Physical Society 2018-02-01
Series:Physical Review X
Online Access:http://doi.org/10.1103/PhysRevX.8.011018
Description
Summary:Quantum logic gates are fundamental building blocks of quantum computers. Their integration into quantum networks requires strong qubit coupling to network channels, as can be realized with neutral atoms and optical photons in cavity quantum electrodynamics. Here we demonstrate that the long-range interaction mediated by a flying photon performs a gate between two stationary atoms inside an optical cavity from which the photon is reflected. This single step executes the gate in 2  μs. We show an entangling operation between the two atoms by generating a Bell state with 76(2)% fidelity. The gate also operates as a cnot. We demonstrate 74.1(1.6)% overlap between the observed and the ideal gate output, limited by the state preparation fidelity of 80.2(0.8)%. As the atoms are efficiently connected to a photonic channel, our gate paves the way towards quantum networking with multiqubit nodes and the distribution of entanglement in repeater-based long-distance quantum networks.
ISSN:2160-3308