Contrôle tout optique d'un fluide quantique de lumière en vapeur atomique chaude

Quantum fluids of light are a novel and promising platform in the exploration of many-body quantum physics. We study here fluids whose constituants are photons. Their interactions are induced by a hot vapor of Rubidium atoms. In order to describe these fluids, we use a Hamiltonian comprising of three terms: kinetic energy, potential energy and interaction energy. In this thesis, we showcase an all-optical control of each of these terms. We evidenced non-classical correlations induced by the interaction quenches at the interfaces of our non-linear medium. We then explore the control of the atomic response of the vapor, using an easily extendable numerical framework. We then use this framework to study optical pumping, that allows us to realize arbitrary potentials inside the fluid of light. The critical velocity for superfluidity is then mesured, in a scattering experiment against an optical defect using the potential engineering developped in this thesis. Finally, we study vortex-vortex interactions in an experiment showcasing turbulent behavior in a fluid of light as well as a collision experiment between vortices. This paves the way to thermodynamics processes seeded by interactions effects beyondthe mean field.Les fluides quantiques de lumière présentent une plateforme nouvelle et prometteuse dans l’exploration de la physique des particules quantiques en interaction. Ici, nous étudions des fluides constitués de photons dont les interactions sont induites par une vapeur chaude de Rubidium. Pour décrire ces fluides, nous recourrons à un hamiltonien comprenant énergie cinétique, énergie potentielle et énergie d’interaction. Nous présentons dans cette thèse un contrôle tout optique de ces fluides où nous agissons sur chaque terme de ce hamiltonien. Nous avons mis en évidence la générations de corrélations non-classiques induites par le saut des interactions aux interfaces de notre milieu non-linéaire. Le contrôle de la réponse du milieu atomique est ensuite exploré en présentant un cadre numérique extensible qui permet de décrire des structures atomiques arbitraires, que nous utilisons ensuite pour décrire l’effet du pompage optique mis en œuvre afin de graver optiquement des potentiels dans le fluide de lumière. Nous caractérisons ensuite les propriétés de superfluidité des fluides de lumière et mesurons la vitesse critique autour d’un défaut créé grâce au contrôle du potentiel induit par pompage optique. Nous concluons en étudiant les interactions entre vortex optiques à travers une expérience mettant en lumière un comportement turbulent du fluide, et une expérience de collision de vortex optiques ouvrant la voie à la thermodynamique induite par des effets quantiques au-delà du champ moyen

Paraxial quantum fluids light in hot atomic vapors

Hot atomic vapors are widely used in non-linear and quantum optics due to their large Kerr non-linearity. This non-linearity induces effective photon-photon interactions allowing light to behave as a fluid displaying quantum properties such as superfluidity. In this presentation, I will show that we have full control over the Hamiltonian that drives the system and that we can engineer an analogue simulator with light

Hot atomic vapors for nonlinear and quantum optics

Nonlinear optics has been a very dynamic field of research with spectacular phenomena discovered mainly after the invention of lasers. The combination of high intensity fields with resonant systems has further enhanced the nonlinearity with specific additional effects related to the resonances. In this paper we review a limited range of these effects which has been studied in the past decades using close-to-room-temperature atomic vapors as the nonlinear resonant medium. In particular we describe four-wave mixing and generation of nonclassical light in atomic vapors. One-and two-mode squeezing as well as photon correlations are discussed. Furthermore, we present some applications for optical and quantum memories based on hot atomic vapors. Finally, we present results on the recently developed field of quantum fluids of light using hot atomic vapors

Analogue cosmological particle creation in an ultracold quantum fluid of light

In inflationary cosmology, the rapid expansion of the early universe resulted in the spontaneous production of cosmological particles from vacuum fluctuations, observable today in the cosmic microwave background anisotropies. The analogue of cosmological particle creation in a quantum fluid could provide insight, but an observation has not yet been achieved. Here we report the spontaneous creation of analogue cosmological particles in the laboratory, using a quenched 3-dimensional quantum fluid of light. We observe acoustic peaks in the density power spectrum, in close quantitative agreement with the quantum-field theoretical prediction. We find that the long-wavelength particles provide a window to early times, and we apply this principle to the cosmic microwave background. This work introduces a new quantum fluid, as cold as an atomic Bose-Einstein condensate.Comment: 7 pages for the main text and 7 pages of supplementary materia