"New Directions in Quantum Optics with Atoms and Nanophotonics" with Prof. Dr. Arno Rauschenbeutel from Humboldt-Universität zu Berlin
Abstract: Simple atom-light systems continue to reveal surprising new phenomena when explored with modern experimental tools. In this talk, I will discuss two recent experiments involving resonance fluorescence and cold atoms coupled to nanophotonic structures.
First, I will revisit resonance fluorescence from a coherently driven two-level emitter. Although this system is often regarded as a fully understood textbook example, our experiments uncover a richer physical picture of photon antibunching based on quantum interference between distinct two-photon scattering pathways. By suppressing the coherently scattered field, we isolate simultaneously scattered photon pairs predicted decades ago but not previously observed directly. I will further show how resonance fluorescence can be converted into a source of high-quality time-bin entangled photon pairs.
Second, I will present a hybrid trapping mechanism for cold atoms near a nanophotonic waveguide that exploits both optical forces and attractive surface interactions. The resulting trap combines efficient loading with long storage and coherence times, illustrating how atom-surface forces can become a useful resource rather than merely a limitation in nanophotonic quantum systems.
These results demonstrate new ways in which engineered atom-light interactions can advance both fundamental quantum optics and future quantum technologies.
