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arXiv · 2007.12014

Engineering multipartite entangled states in doubly pumped parametric down-conversion processes

Alessandra Gatti·Enrico Brambilla·Ottavia Jedrkiewicz
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Abstract

We investigate the quantum state generated by optical parametric down-conversion in a $χ^{(2) } $ medium driven by two noncollinear light modes. The analysis shows the emergence of multipartite, namely 3- or 4-partite, entangled states in a subset of the spatio-temporal modes generated by the process. These appear as bright spots against the background fluorescence, providing an interesting analogy with the phenomenology recently observed in two-dimensional nonlinear photonic crystals. We study two realistic setups: i) Non-critical phase-matching in a periodically poled Lithium Tantalate slab, characterized by a 3-mode entangled state among hot spots. ii) A type I setup in a Beta-Barium Borate crystal, where the spatial walk-off between the two pumps can be exploited to make a transition to a quadripartite entangled state. In both cases we show that the properties of the state can be controlled by modulating the relative intensity of two pump waves, making the device a versatile tool for quantum state engineering.

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Alessandra Gatti, Enrico Brambilla, Ottavia Jedrkiewicz. 2020-11-19. Engineering multipartite entangled states in doubly pumped parametric down-conversion processes. https://doi.org/10.1103/physreva.103.043720

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