Long-distance distribution of atom-photon entanglement at telecom wavelength

Entanglement between stationary quantum memories and photonic channels is the essential resource for future quantum networks. Together with entanglement distillation it will enable for efficient distribution of quantum states. Here we report on the generation and observation of entanglement between...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2019-09
Main Authors: Tim van Leent, Bock, Matthias, Garthoff, Robert, Redeker, Kai, Zhang, Wei, Bauer, Tobias, Rosenfeld, Wenjamin, Becher, Christoph, Weinfurter, Harald
Format: Article
Language:English
Subjects:
Atomic states
Conversion
Distillation
Optical fibers
Photonics
Photons
Quantum entanglement
Quantum phenomena
Superhigh frequencies
Telecommunications
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Entanglement between stationary quantum memories and photonic channels is the essential resource for future quantum networks. Together with entanglement distillation it will enable for efficient distribution of quantum states. Here we report on the generation and observation of entanglement between a Rb-87 atom and a photon at telecom wavelength over 20 km optical fiber. For this purpose, we use polarization-preserving quantum frequency conversion to transform the wavelength of a photon entangled with the atomic spin state from 780 nm to the telecom S-band at 1522 nm. We achieve an unprecedented external device conversion efficiency of 57% and observe an entanglement fidelity between the atom and telecom photon of \(\geqslant\)78.5\(\pm\)0.9% over 20 km optical fiber, mainly limited by decoherence of the atomic state. This result is an important milestone on the road to distribute quantum information on a large scale.
ISSN:2331-8422
DOI:10.48550/arxiv.1909.01006