Quantum Optics Seminar: Stefanie Barz

Quantum photonics: interference beyond HOM, entanglement, and quantum networks

I will start by introducing the key principles of photonic quantum technologies, and then show a series of recent results on different aspects of those. Starting with quantum optics and quantum foundations, I will then introduce experiments on quantum networks both on the hardware and software side.  

In particular, I will first be talking about quantum interference - a central ingredient of photonic quantum technologies. I will discuss novel aspects quantum interference and demonstrate how two fundamental properties of quantum states, distinguishability and mixedness, impact the interference of multiple single photons. I will then show how we can exploit interference of single photons to generate multipartite entangled quantum states and present a novel method that allows switching between different types of states by just local single-photon operations.

Second, I will show how photon interference and entangled states can be used in quantum networks. I will talk about a crucial component of a photonic quantum network: Bell-state measurements and report on an experimental demonstration of a scheme that allows obtaining a success probability of more than 50%. Finally, I will show multipartite entanglement can lead to an advantage in networked quantum communication.