From multi-photon entanglement generation to a physical graph representation: conceptual understanding and automated design of quantum optics experiments
Quantum mechanics predicts many phenomena that seem counterintuitive from our classical physics perspective. Entanglement is one of the phenomena which plays an important role in quantum technologies ranging from communication to computation. Quantum experiments, whether for fundamental or practical ends, are unquestionably crucial to the investigation of these phenomena. Finding setups for multi-photon entanglement is a conceptual challenge for human scientists due to the counterintuitive behavior of multiparticle interference and the enormously large combinatorial search space. Recently, new possibilities have been opened by artificial discovery where artificial intelligence proposes experimental setups for the creation and manipulation of high-dimensional multi-particle entanglement. The results of quantum experiments are perfectly computable but difficult to intuitively understand. In this talk, I will introduce a hidden connection between quantum optics experiments and the mathematical field of Graph Theory, and show how one can model and understand phenomena from modern-day photonic quantum experiments. There, a colored weighted graph can capture all the information of a quantum optical experiment. The graph can be translated back at any point to an experiment consisting of optical elements, and I will show how to translate it into several quantum optical experiments. This physical and abstract graph representation allows us to discover various quantum information tasks. With the graph-based representation of optical setups, we further develop PyTheus, an open-source, automated design and digital discovery framework for quantum optics experiments. I will showcase the applicability of PyTheus with different examples and hope it helps accelerate the development of quantum optics and offer new ideas in quantum technology.
In general, our physical graph representation of optical setups gives us a very different perspective on photonic quantum technology, and is significantly useful for the design of future quantum experiments and applications in quantum information.