Demonstration of controllable temporal distinguishability in a three-photon stateB. H. Liu1, F. W. Sun1, Y. X. Gong1, Y. F. Huang1, Z. Y. Ou1, 2 and G. C. Guo1
1 Key Laboratory of Quantum Information, University of Science and Technology of China, CAS - Hefei 230026, PRC
2 Department of Physics, Indiana University-Purdue University Indianapolis - 402 N. Blackford Street, Indianapolis, IN 46202, USA
received 7 September 2006; accepted in final form 23 November 2006; published January 2007
published online 17 January 2007
By using two processes of parametric down-conversion, we are able to generate three photons with controllable degree of temporal distinguishability. This is confirmed by the visibility in a three-photon interference experiment, which can be generalized to provide a practical technique for characterizing the temporal distinguishability of a multi-photon state. This method of quantitative description of multi-photon indistinguishability will have practical implications in the implementation of quantum information protocols.
42.50.Dv - Nonclassical states of the electromagnetic field, including entangled photon states; quantum state engineering and measurements .
03.67.Mn - Entanglement production, characterization, and manipulation .
42.50.St - Nonclassical interferometry, subwavelength lithography .
© Europhysics Letters Association 2007