Quantum optics

The quest for higher dimensionality

Using a clever design of polarization optic, Italian researchers have successfully created four-level 'ququart' quantum states using the polarization and orbital angular momentum of single photons. This approach may help to realize more effective forms of quantum communication.

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Figure 1: The q-plate is a half-wave plate with an optical axis that has a spatially varying orientation, as indicated by the dark blue concentric circles (and the red vector for one example location).


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Correspondence to Stanislav Straupe.

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Straupe, S., Kulik, S. The quest for higher dimensionality. Nature Photon 4, 585–586 (2010). https://doi.org/10.1038/nphoton.2010.215

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