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arXiv · 2404.16025

Birefringent spin-photon interface generates polarization entanglement

Nikita Leppenen·Dmitry S. Smirnov
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Abstract

A spin-photon interface based on the luminescence of a singly charged quantum dot in a micropillar cavity allows for the creation of photonic entangled states. Current devices suffer from cavity birefringence, which limits the generation of spin-photon entanglement. In this paper, we theoretically study the light absorption and emission by the interface with an anisotropic cavity and derive the maximal excitation and spin-photon entanglement conditions. We show that the concurrence of the spin-photon state equal to one and complete quantum dot population inversion can be reached for a micropillar cavity with any degree of birefringence by tuning the quantum dot resonance strictly between the cavity modes. This sweet spot is also valid for generating a multiphoton cluster state, as we demonstrate by calculating the three-tangle and fidelity with the maximally entangled state.

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Nikita Leppenen, Dmitry S. Smirnov. 2024-04-24. Birefringent spin-photon interface generates polarization entanglement. https://doi.org/10.1002/qute.202400193

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