From bipartite to many-particle entanglement of ultracold atoms

• Applicant: Professor Dr. Carsten Klempt
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 283618181

Within this project, we will explore the creation of entangled atomic states using spin dynamics in Bose-Einstein condensates. We will implement an atomic homodyning technique to investigate the striking non-classical properties of the created states on the single-particle level and thereby gain important insights on the fundamental microscopic processes. We will investigate the creation of entangled states from entangled atom pairs to large clusters of entangled atoms.Continuous variable entanglement will be revealed by atomic homodyne measurements and improved to obtain a high degree of Einstein-Podolsky-Rosen (EPR) entanglement. The entanglement of the created states will be demonstrated by a tomographic reconstruction of the quantum state with single-particle precision. We will observe the Hong-Ou-Mandel (HOM) effect in the interference of atom pairs by coupling the entangled particles. Both the EPR entanglement and the HOM effect will be studied for an increasing number of particles and methods for the characterization of the resulting mesoscopic states will be developed. Finally, the creation of Schrödinger kitten states by a combination of spin dynamics and microwave coupling will be investigated.In summary, the project provides a new path to explore the transition from few- to many-particle entanglement with the exciting perspective to probe the onset of classicality in macroscopic quantum systems.

• DFG Programme: Research Grants