Generating entangled states of two ququarts using linear optical elements
So-Young Baek, Yoon-Ho Kim · International Conference on Quantum Information · 2007
We propose linear-optical schemes for generating entangled-states of two ququarts (four-dimensional quantum systems) in which single-ququart states are constructed with frequency-nondegenerate biphoton polarization states of spontaneous parametric down-conversion. The schemes require beamsplitters and coincidence post-selection.