Entangled photons are a cornerstone of quantum technologies, enabling applications from secure communication to quantum computing. Ferroelectric nematic liquid crystals are promising materials for such sources, due to their nonlinear optical properties and easily controllable configuration. Nerea Sebastian together with Sara Klopčič, Aljaž Kavčič and dr. Matjaž Humar from Lab for biophotonics, soft photonics and quantum optics and Condensed matter physics department at Jožef Stefan Institute and Faculty of Mathematics and Physics at the University of Ljubljana have demonstrated, in a recently published article “Electrically and Geometrically Tunable Photon Pair Entanglement from Ferroelectric Nematic Liquid Crystal” in Advanced Science, that quantum-entangled photon pairs can be generated in ferroelectric nematic liquid crystals (FNLCs), while simultaneously allowing continuous control over the degree of quantum entanglement. This control can be achieved by adjusting the sample thickness and molecular twist, or in real-time by applying an external electric field. Such continuous and real-time tunability represents an important advantage of liquid crystals over classical solid nonlinear crystals and paves the way for the development of so-called quantum displays.
The full text can be found at: https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/advs.202515206