Characterization and Preparation of Higher Photon Number States

Mohammad Hafezi

Kaisa Laiho, Malte Avenhaus, Christine Silberhorn

We investigate up to the fourth order normalized factorial moments of free-propagating and pulsed single photons displaced in phase space in a phase-averaged manner. Due to their loss independence, these moments offer expedient methods for quantum optical state characterization. We examine quantum features of the prepared displaced states, retrieve information on their photon-number content and study the reliability of the state reconstruction method used.

Noboru Watanabe

Петер Адам, József Janszky, P. Domokos +1 more

It is shown that the deflection of an atom de Broglie wave at two adjacent cavities containing non-resonant weak fields can yield a highly entangled quantum state of the atom–field system in which discernible atomic beams are entangled to internal states of the atom and to two-mode photon-number states of the fields. Two-mode anticorrelated entangled photon-number states characterized by the total photon number can be prepared by the detection of the atom in given directions of the propagation.

Akira Kitagawa

Christine Silberhorn, Daryl Achilles, Konrad Banaszek

Parametric downconversion inaquasi-phase matched KTPwaveguide offers thepossibility toimplement ahighly efficient source ofphotonic states. Weinvestigate thephoton statistics ofsuch asource with atime-multiplexed detector, which iscapable ofphoton number resolution. Parametric downconversion (PDC)sources havebecomeanestablished technique togenerate single photon states. InthePDCprocess pairs ofphotons canbeproduced indistinguishable modes(oforthogonal polarization) suchthat thedetection ofonephoton will herald thepresence oftheother intheconjugate mode.There have always beentwoproblems hindering progress inpreparing higher order photon number states: thelack ofhighly efficient PDCsources andphoton-number resolving detectors. Wedemonstrate approaches tostudy these problems, andshowtheexperimental generation oftwo-photon states withhighfidelity byconditional state preparation. Weutilize atime-multiplexed detector, whichisfiber based andoperates ontheprinciple ofdetector cascading, inconjunction with abright highly efficient waveguided, typeIIPDCsource, which wepumpwithultrashort pulses. ThePDCstate canbedescribed by 00