Experimental demonstration of high two-photon time-energy entanglement
Irfan Ali Khan, John C. Howell · Physical Review A · 2006
We report on the experimental demonstration of high energy-time entanglement in two-photon states created in the process of spontaneous parametric down-conversion. We show that the classical variance product, which we violate by three orders of magnitude, actually represents a lower bound estimate of the number of information eigenmodes $K$. Explicit measurements estimate $K$ to be greater than 100, with theoretical estimates predicting a value of as high as $1\ifmmode\times\else\texttimes\fi{}{10}^{6}$. These results provide incentive for the practical feasibility of large bandwidth quantum information processing, particularly in cryptography over large distances.