Preparation and characterization of arbitrary states of four-dimensional qudits based on biphotons

Abstract

We report interferometric schemes to prepare arbitrary states of four-dimensional qudits (ququarts) based on biphoton states of ultrafast-pumped frequency-nondegenerate spontaneous parametric down-conversion. Preparation and tomographic characterization of a few examples of general single-ququart states, a pure state, a completely mixed state, and a partially-mixed state, are experimentally demonstrated.

References in corpus (5)

• Experimental Realization of Polarization Qutrits from Non-Maximally Entangled States
• Characteristics and benchmarks of entanglement of mixed states -- the two qubit case
• Greenberger-Horne-Zeilinger-type violation of local realism by mixed states
• Maximal violation of Clauser-Horne-Shimony-Holt inequality for four-level systems
• Scalable scheme for entangling multiple ququarts using linear optical elements