Nonlinear optics as a source of high-dimensional genuine tripartite entanglement

Abstract

We lay down a general scheme to quantify the amount of genuine tripartite entanglement present in the spatial and energy-time degrees of freedom using the correlations naturally present in many such sources. To that end, we test our method using the three-photon states generated in three-party extensions of spontaneous parametric down-conversion, and demonstrate that a substantial amount of spatial and energy-time genuine tripartite entanglement can exist for reasonable experimental sources.

Optomechanical Microwave-to-Optical Photon Transducer Chips: Empowering the Quantum Internet Revolution

“…Radiation pressure, which involves the momentum transfer of photons, fundamentally links the behavior of the optical radiation field within a cavity to its mechanical dynamics. The Hamiltonian describing a coupled system of an optical cavity and microwave resonator resonating at ω o and ω e , respectively, interacting with a mechanical resonator oscillating at ω m , is [4,[43][44][45]…”

“…Compared to membrane, phononic crystal-based transducers often have larger bandwidths (∼MHz), especially in the portion of the structure leveraging the piezoelectric effect. The primary advantage of phononic crystal resonators lies in their compatibility, which allows for support of various optomechanical coupling structures and diverse material selections, offering limitless possibilities for further system development [4,74,75]. Furthermore, transducers utilizing the piezoelectric effect usually exhibit lower noise than electro-optic ones and often do not require complex active cooling techniques [22,[76][77][78].…”

“…Microwave-optical quantum transducer may be a good solution to this problem. Although quantum information processing typically operates at microwave frequencies, the most mature long-distance information transmission systems currently available are optical fibers, and the loss of transmitting photons through optical fibers is much lower in coaxial cables [4]. Therefore, developing transducer chips that efficiently couple microwave photons with telecom photons is critical.…”