Quantum simulation of strong interactions of light and matter
Valentin Klüsener – Hector Fellow Immanuel Bloch
The central paradigm of quantum optics is the absorption and emission of radiation by quantum emitters. When the coupling between an emitter and its environment becomes strong, intriguing radiative properties can be engineered, such as directional emission patterns or strongly modified emission rates. This project aims at accessing such effects in a system of ultracold atoms in optical lattices where artificial emitters decay by emitting matter waves rather than optical radiation.
Analog quantum simulation allows studying complex quantum many-body systems by realizing the system of interest in a clean and precisely controllable setting of quantum particles. This avenue has been successfully pursued using ultracold atoms in optical lattices to study strongly correlated condensed matter systems. This project aims at extending the capabilities of this platform to simulations in the fields of quantum optics and nanophotonics. The central paradigm of quantum optics is the absorption of radiation by quantum emitters and subsequent emission into the surrounding environment. When the coupling between an emitter and its environment becomes strong, many-body quantum systems with interesting radiative properties can be engineered, such as directional emission patterns or exceptionally long-lived “subradiant” states.
These phenomena will be investigated by replacing the quantum emitter by an artificial two-level system of ultracold atoms in a state-dependent optical lattice. Trapped atoms in a metastable excited state will act as emitters, which can decay by “emitting” bath particles, corresponding to matter waves of ground state atoms. To study the dynamics of these bath particles the ground state atoms will be imaged with single-atom resolution. The proposed analog quantum simulator will enable the study of strongly coupled light-matter interfaces, which are inaccessible in state-of-theart nanophotonic devices.
A trapped cloud of ultracold strontium atoms at temperatures close to absolute zero (left). Artist’s impression of emission of matter waves (bath particles) in a system of artificial emitters in an optical lattice (right).
Valentin KlüsenerLudwig-Maximilians-Universität Munich
Hector Fellow since 2012