Interfacing interacting Rydberg polaritons: From few- to many-body interactions

Descrizione del progetto

Da poche a molte quasiparticelle esotiche a disposizione di reti e calcoli computazionali

Gli atomi di Rydberg hanno un singolo elettrone di valenza esterno che può essere eccitato a stati quantistici superiori. In pratica, questo significa che l’elettrone è in grado di spostarsi molto lontano dal nucleo, aumentando il raggio atomico di un miliardo di volte e facilitando interazioni straordinarie con gli atomi vicini pur rimanendo legato al proprio nucleo. Questi atomi di Rydberg possono anche interagire con singoli fotoni per creare polaritoni di Rydberg fortemente interagenti. Il controllo di queste interazioni apre la porta a dispositivi ottici quantistici innovativi e il progetto InterPol, finanziato dall’UE, sta alzando la posta. Passando dallo studio sperimentale di pochi polaritoni a molti, il team si sta avvicinando sempre di più a dispositivi di calcolo quantistico basati sui polaritoni.

Obiettivo

Rydberg quantum optics (RQO) is a very promising approach to achieve effective interactions at the level of individual photons. It maps the strong interactions between ultracold Rydberg atoms onto light fields to create strongly interacting Rydberg polaritons. RQO enables single photon generation, exotic photon bound states, and effective interactions between spatially separated photons. Based on RQO, various quantum optical devices can be implemented, e.g. a deterministic gate for optical quantum information processing. Experiments to date have mostly used 1D interaction geometries and not yet investigated interactions between more than 2 or 3 polaritons or in a quantum network of interaction nodes. InterPol will implement controlled interactions between multiple Rydberg polaritons based on two complementary approaches. One will cascade multiple devices such as single-photon transistors and subtractors to implement multi-polariton logic circuits and demonstrate a network that coherently interfaces entangled Rydberg excitations with photons for quantum state transfer. The second will use adaptive optics to realize a novel, highly flexible platform to study simultaneous interactions between multiple polaritons in arbitrary spatial geometries to study the transition regime from few- to many-body interactions. This has fundamental impact beyond quantum optics as it will allow highly controlled experimental tests of many-body interactions and non-perturbative effects in quantum field theories with quasi-particles in a tabletop setting. Collaborating with leading theorists to experimentally benchmark field-theoretical descriptions, the applicant will further deepen his theoretical understanding of RQO to complement his excellent experimental skills. In charge of a comprehensive research action, he will enhance his independence and possess the skill set required to develop and conduct innovative quantum optics experiments as an independent researcher at its end.