Experimental Test of Fidelity Limits in Six-Photon Interferometry and of Rotational Invariance Properties of the Photonic Six-Qubit Entanglement Singlet State
2009 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 103, no 150501Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2009. Vol. 103, no 150501
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-33050DOI: 10.1103/PhysRevLett.103.150501ISI: 000270672100001OAI: oai:DiVA.org:su-33050DiVA: diva2:282275