Q-CORR_Quantum Correlations - from Few to Many Particles

• Applicant: Professor Dr. Harald Weinfurter
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 381445721

Quantum entanglement is at the core of the new features and benefits of quantum physics. Its direct manifestation in our classical world are correlations between measurement results much stronger than what is possible within classical physics. These correlations allow to explore the foundations of quantum mechanics and at the same time can be harnessed for the many applications in quantum metrology and information processing. Significant progress has been made for understanding and applying correlations between pairs of quantum systems. However, for a higher number of entangled particles the observed correlations are far more complex. The exponentially increasing costs for determining crucial parameters cause a huge obstacle for the evaluation of experiments and for applications with a growing number of quantum systems, not the least due to a still unsatisfactory definition of multiparty quantum correlations.The aim of our project is thus to design efficient methods for revealing and applying quantum correlations in large systems and to advance the understanding of these unique quantum features. The main objectives of Q-CORR are to- investigate the operational definition and measure of multipartite correlations- develop efficient and self-learning procedures for quantum state reconstruction robust against experimental imperfections - design efficient methods for entanglement detection for limited resources, e.g. for a small number of measurements or not individually addressable particles- apply the improved strategies to quantum metrology going well beyond the shot-noise limit.Thanks to the longstanding cooperation between our Polish and German groups as well as between theory and experiment the teams joined within Q-CORR are in an ideal situation to tackle current problems. Novel theoretical results will be first demonstrated with photonic experiments and further developed for being applicable to any quantum system. More efficient, flexible and noise-resistant methods will foster applications of large quantum systems. Q-CORR will go well beyond current state-of-the-art in theoretical concepts, numerical simulations and experiments, making complex systems and realistic experimental environments accessible for future research.

• DFG Programme: Research Grants
• International Connection: Poland
• Partner Organisation: Narodowe Centrum Nauki (NCN)
• Co-Investigator: Professorin Dr. Jasmin Meinecke
• Cooperation Partners: Wieslaw Laskowski, Ph.D.; Marcin Marek Markiewicz, Ph.D.; Marcin Adam Wiesniak, Ph.D.