IS THERE REALLY AN ENTANGLED STATE FOR FAR AWAY TWIN PHOTONS?

Yanhua H. Shih

Shiming Gao, Changxi Yang, Daru Chen +2 more

We theoretically present the bandwidth enhancement methods of the telecom-region entangled twin photons generated by quasi-phase-matched (QPM) spontaneous parametric down-conversion (SPDC) in periodically poled lithium niobate (PPLN) crystals. By using type I (e → e + e) SPDC, the degenerate entangled twin photons will have a broad bandwidth and it can be further enhanced by shortening the crystal length, detuning the pump wavelength or adjusting the working temperature of the PPLN crystal. This principle provides the possibility to introduce wavelength-division-multiplexed technique into quantum information systems.

Luiz Carlos Ryff

Otgonbaatar Myagmar, Duger Ulam-Orgikh, Purevdorj Munkhbaatar

Krishna Thyagarajan