Ultrafast and Cooperative Light-Matter Coupling

Daniel T. Payne

Drawing around 140 attendees to the serene hills of Tuscany, Italy, February’s Gordon Research Conference (GRC) on Ultrafast Phenomena in Cooperative Systems explored recent advances in the understanding of light-induced phases of condensed matter.

Le Gouët

Dmitry Panna, Nadav Landau, Liron Gantz +7 more

We demonstrate ultrafast control of a strongly coupled light–matter system via a giant ac Stark effect in a specially designed strongly coupled microcavity using ultrafast pump–probe spectroscopy. We observe polariton energy shifts larger than the Rabi energy, enabling the implementation of strong noninvasive potentials for robust and ultrafast polaritonic switches. A nonperturbative treatment has been utilized to correctly describe the underlying physics of the giant Stark shifts in our strongly coupled light–matter system and corresponds well to the experimental results. Our findings shed new light on nonperturbative interactions and pave the way for all-optical quantum technologies.

Jean-Louis Le Gouët

Kochise Bennett

Spectroscopy, the study of matter via its interactions with light, is a vast subject that includes many of humanity's principle means of probing the fundamental structure of matter. Though usually understood from the perspective of classical light, important effects arise due to the quantum nature of the electromagnetic field. Additionally, the quantum vacuum can serve as an effective couple between molecules in the system, generating many-body interactions and cooperative processes in the material. While many techniques are well-described classically, quantum-field corrections can dominate the desired signals in certain cases, such as cascading in higher-order n-wave mixing signals, and are key for experimental interpretation. Even spontaneous emission and light scattering are best understood from the perspective of quantum fields. In this thesis, we utilize a systematic procedure, based on the density matrix in Liouville space, to give a rigorous description of elementary quantum-field effects in nonlinear spectroscopy, with specific examples made to ultrafast x-ray and optical techniques.

Anonymous