• Featured in Physics

Experimental Test of Fidelity Limits in Six-Photon Interferometry and of Rotational Invariance Properties of the Photonic Six-Qubit Entanglement Singlet State

Magnus Rådmark, Marek Żukowski, and Mohamed Bourennane
Phys. Rev. Lett. 103, 150501 – Published 5 October 2009
Physics logo See Viewpoint: Protecting quantum superpositions from the outside world

Abstract

Quantum multiphoton interferometry has now reached the six-photon stage. Thus far, the observed fidelities of entangled states never reached 2/3. We report a high fidelity (estimated at 88%) experiment in which six-qubit singlet correlations were observed. With such a high fidelity we are able to demonstrate the central property of these “singlet” correlations, their “rotational invariance,” by performing a full set of measurements in three complementary polarization bases. The patterns are almost indistinguishable. The data reveal genuine six-photon entanglement. We also study several five-photon states, which result upon detection of one of the photons. Multiphoton singlet states survive some types of depolarization and are thus important in quantum communication schemes.

  • Figure
  • Figure
  • Figure
  • Received 18 March 2009

DOI:https://doi.org/10.1103/PhysRevLett.103.150501

©2009 American Physical Society

Viewpoint

Key Image

Protecting quantum superpositions from the outside world

Published 5 October 2009

An entangled state of six photons could potentially carry quantum information over large distances and between different reference frames.

See more in Physics

Authors & Affiliations

Magnus Rådmark1, Marek Żukowski2, and Mohamed Bourennane1

  • 1Physics Department, Stockholm University, SE-10691 Stockholm, Sweden
  • 2Institute for Theoretical Physics and Astrophysics, Uniwersytet Gdański, PL-80-952 Gdańsk, Poland

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 103, Iss. 15 — 9 October 2009

Reuse & Permissions
Access Options

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×