Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1412.5405 · Physical Review A

Propagation of a quantum fluid of light in a cavityless nonlinear optical medium: General theory and response to quantum quenches

Pierre-Élie Larré, Iacopo Carusotto

Published Oct 2, 2015• 75 citations
arXivHTMLPDF

Abstract

Making use of a generalized quantum theory of paraxial light propagation where the radiation-axis and the temporal coordinates play exchanged roles, we discuss the potential of bulk nonlinear optical media in cavityless configurations for quantum statistical mechanics studies of the conservative many-body dynamics of a gas of interacting photons. To illustrate the general features of this point of view, we investigate the response of the fluid of light to the quantum quenches in the photon-photon interaction constant experienced at the front and the back faces of a finite slab of weakly nonlinear material. Extending the standard Bogoliubov theory of dilute Bose-Einstein condensates, peculiar features are predicted for the statistical properties of the light emerging from the nonlinear medium.

DOI
10.1103/physreva.92.043802

Related papers

Thermalization and Bose-Einstein condensation of quantum light in bulk nonlinear media

A. Chiocchetta, Pierre-Élie Larré, Iacopo Carusotto

We study the thermalization and the Bose-Einstein condensation of a paraxial, spectrally narrow beam of quantum light propagating in a lossless bulk Kerr medium. The spatiotemporal evolution of the quantum optical field is ruled by a Heisenberg equation analogous to the quantum nonlinear Schrödinger equation of dilute atomic Bose gases. Correspondingly, in the weak-nonlinearity regime, the phase-space density evolves according to the Boltzmann equation. Expressions for the thermalization time and for the temperature and the chemical potential of the eventual Bose-Einstein distribution are found. After discussing experimental issues, we introduce an optical setup allowing the evaporative cooling of a guided beam of light towards Bose-Einstein condensation. This might serve as a novel source of coherent light.

arXiv:1605.01870•Europhysics Letters (EPL)•Jul 1, 2016•33 citations

Nonlinear dynamics in quantum fluids of light

Heitor Victor Santos da SILVA

The propagation of light in nonlinear media is well described by a 2D nonlinear Schrödinger equation (NLSE) within the paraxial approximation, which is equivalent to the GrossPitaevskii equation (GPE), the mean-field description for the dynamics of Bose-Einstein condensates (BECs). As a product of this similarity, we can establish the figure of a quantum fluid of light. Quantum fluids of light have been used for theoretical and experimental investigations of phenomena already studied and realised in BECs. In this thesis, we describe the mechanisms that make the conception of a quantum fluid of light possible for different experimental platforms. Furthermore, we present a study on the formation of self-bound droplets of light in hot atomic vapours, our chosen nonlinear medium, in an attempt to obtain a mapping between experimental parameters typically used in BEC experiments and those needed to observe the analogous phenomenon in atomic vapours. We investigate the static properties of the system, providing a phase diagram for the different and possible solutions for the optical regimes of interest. Finally, we systematically study droplet dynamics, focusing on the behaviour of the collective monopole excitation and the dynamic formation of these objects under realistic experimental conditions.

•Jul 25, 2023•0 citations

Turbulence excitation in counterstreaming paraxial superfluids of light

João D. Rodrigues, José Tito Mendonça, Hugo Terças

Turbulence in the quantum (superfluid) regime, similarly to its classical counterpart, continues to attract a great deal of scientific inquiry due to the yet high number of unresolved problems. While turbulent states can be routinely created in degenerate atomic gases, there is no generic scheme to produce turbulence in fluids of light. Under paraxial propagation, light in bulk nonlinear media behaves as a two-dimensional superfluid, described by a nonlinear Schr\"odinger equation formally equivalent to the Gross-Pitaevskii model of a weakly interacting Bose gas, where photon-photon interactions are mediated by a third-order (Kerr) nonlinearity. Here we develop the theory describing the onset of a kinetic instability when two paraxial optical fluids with different streaming velocities interact via the optical nonlinearity. From numerical simulations of the nonlinear Schr\"odinger equation, we further characterize the onset of the instability and describe its saturation in the form of vortex nucleation and excitation of turbulence. The experimental observation of such effects is also discussed. The class of instabilities described here thus provide a natural route towards the investigation of quantum (superfluid) turbulence, structure formation, and out-of-equilibrium dynamics in superfluids of light.

arXiv:1802.05553•Physical Review A•Apr 9, 2020•20 citations

Paraxial fluid of light in hot atomic vapors

Quentin Fontaine

Quantum fluids of light are the photonic counterpart of Bose gases. They currently attract increasing interest since they are versatile and highly tunable systems for probing many-body physics quantum phenomena, such as superfluidity. Superfluid flow of light has already been reported in microcavity exciton-polariton condensates but clear observation of this phenomenon in cavityless systems, that is, for propagating photon fluids, remains elusive. In this thesis, we study the hydrodynamical properties of light propagating close to resonance in hot rubidium vapors. Whereas photons in air are not interacting with each other, the situation is different in rubidium vapors, as an effective interaction between them, mediated by the atomic ensemble, appears. The light behaves therefore as a fluid flowing in the plane perpendicular to the optical axis. The primary purpose of this thesis was to show that light in those systems can behave as a superfluid. The first step toward the observation of superfluidity is to measure the dispersion relation of small amplitude density waves travelling onto the propagating photon fluid. I show that this dispersion exhibits a linear trend for small excitation wave-vectors, which is, according to the Landau criterion, a sufficient condition for guaranteeing superfluidity. I present then an all-optical defect experiment - where the photon fluid flows against an optically induced obstacle (namely, a local change of refractive index) - designed to measure the drag force cancellation at the fluid/superfluid threshold.

arXiv:2011.12126•Nov 24, 2020•0 citations

Observation of the Bogoliubov Dispersion in a Fluid of Light

Quentin Fontaine, Tom Bienaimé, Simon Pigeon +3 more

Quantum fluids of light are a photonic counterpart to atomic Bose gases and are attracting increasing interest for probing many-body physics quantum phenomena such as superfluidity. Two different configurations are commonly used: the confined geometry where a nonlinear material is fixed inside an optical cavity and the propagating geometry where the propagation direction plays the role of an effective time for the system. The observation of the dispersion relation for elementary excitations in a photon fluid has proved to be a difficult task in both configurations with few experimental realizations. Here, we propose and implement a general method for measuring the excitations spectrum in a fluid of light, based on a group velocity measurement. We observe a Bogoliubov-like dispersion with a speed of sound scaling as the square root of the fluid density. This Letter demonstrates that a nonlinear system based on an atomic vapor pumped near resonance is a versatile and highly tunable platform to study quantum fluids of light.

arXiv:1807.10242•Physical Review Letters•Oct 31, 2018•110 citations

Squeezing in a nonlocal photon fluid

Maria Chiara Braidotti, Antonio Mecozzi, Claudio Conti

Quantum fluids of light are an emerging tool employed in quantum many-body physics. Their amazing properties and versatility allow using them in a wide variety of fields including gravitation, quantum information, and simulation. However the implications of the quantum nature of light in nonlinear optical propagation are still missing many features. We theoretically predict classical spontaneous squeezing of a photon fluid in a nonlocal nonlinear medium. By using the so called Gamow vectors, we show that the quadratures of a coherent state get squeezed and that a maximal squeezing power exists. Our analysis holds true for temporal and spatial optical propagation in a highly nonlocal regime. These results lead to advances in the quantum photon fluids research and may inspire applications in fields like metrology and analogs of quantum gravity.

arXiv:1611.01793•Physical Review A•Oct 10, 2017•7 citations
Making use of a generalized quantum theory of paraxial light propagation where the radiation-axis and the temporal coordinates play exchanged roles, we discuss the potential of bulk nonlinear optical media in cavityless configurations for quantum statistical mechanics studies of the conservative many-body dynamics of a gas of interacting photons. To illustrate the general features of this point of view, we investigate the response of the fluid of light to the quantum quenches in the photon-photon interaction constant experienced at the front and the back faces of a finite slab of weakly nonlinear material. Extending the standard Bogoliubov theory of dilute Bose-Einstein condensates, peculiar features are predicted for the statistical properties of the light emerging from the nonlinear medium.
We study the thermalization and the Bose-Einstein condensation of a paraxial, spectrally narrow beam of quantum light propagating in a lossless bulk Kerr medium. The spatiotemporal evolution of the quantum optical field is ruled by a Heisenberg equation analogous to the quantum nonlinear Schrödinger equation of dilute atomic Bose gases. Correspondingly, in the weak-nonlinearity regime, the phase-space density evolves according to the Boltzmann equation. Expressions for the thermalization time and for the temperature and the chemical potential of the eventual Bose-Einstein distribution are found. After discussing experimental issues, we introduce an optical setup allowing the evaporative cooling of a guided beam of light towards Bose-Einstein condensation. This might serve as a novel source of coherent light.
The propagation of light in nonlinear media is well described by a 2D nonlinear Schrödinger equation (NLSE) within the paraxial approximation, which is equivalent to the GrossPitaevskii equation (GPE), the mean-field description for the dynamics of Bose-Einstein condensates (BECs). As a product of this similarity, we can establish the figure of a quantum fluid of light. Quantum fluids of light have been used for theoretical and experimental investigations of phenomena already studied and realised in BECs. In this thesis, we describe the mechanisms that make the conception of a quantum fluid of light possible for different experimental platforms. Furthermore, we present a study on the formation of self-bound droplets of light in hot atomic vapours, our chosen nonlinear medium, in an attempt to obtain a mapping between experimental parameters typically used in BEC experiments and those needed to observe the analogous phenomenon in atomic vapours. We investigate the static properties of the system, providing a phase diagram for the different and possible solutions for the optical regimes of interest. Finally, we systematically study droplet dynamics, focusing on the behaviour of the collective monopole excitation and the dynamic formation of these objects under realistic experimental conditions.
Turbulence in the quantum (superfluid) regime, similarly to its classical counterpart, continues to attract a great deal of scientific inquiry due to the yet high number of unresolved problems. While turbulent states can be routinely created in degenerate atomic gases, there is no generic scheme to produce turbulence in fluids of light. Under paraxial propagation, light in bulk nonlinear media behaves as a two-dimensional superfluid, described by a nonlinear Schr\"odinger equation formally equivalent to the Gross-Pitaevskii model of a weakly interacting Bose gas, where photon-photon interactions are mediated by a third-order (Kerr) nonlinearity. Here we develop the theory describing the onset of a kinetic instability when two paraxial optical fluids with different streaming velocities interact via the optical nonlinearity. From numerical simulations of the nonlinear Schr\"odinger equation, we further characterize the onset of the instability and describe its saturation in the form of vortex nucleation and excitation of turbulence. The experimental observation of such effects is also discussed. The class of instabilities described here thus provide a natural route towards the investigation of quantum (superfluid) turbulence, structure formation, and out-of-equilibrium dynamics in superfluids of light.
Quantum fluids of light are the photonic counterpart of Bose gases. They currently attract increasing interest since they are versatile and highly tunable systems for probing many-body physics quantum phenomena, such as superfluidity. Superfluid flow of light has already been reported in microcavity exciton-polariton condensates but clear observation of this phenomenon in cavityless systems, that is, for propagating photon fluids, remains elusive. In this thesis, we study the hydrodynamical properties of light propagating close to resonance in hot rubidium vapors. Whereas photons in air are not interacting with each other, the situation is different in rubidium vapors, as an effective interaction between them, mediated by the atomic ensemble, appears. The light behaves therefore as a fluid flowing in the plane perpendicular to the optical axis. The primary purpose of this thesis was to show that light in those systems can behave as a superfluid. The first step toward the observation of superfluidity is to measure the dispersion relation of small amplitude density waves travelling onto the propagating photon fluid. I show that this dispersion exhibits a linear trend for small excitation wave-vectors, which is, according to the Landau criterion, a sufficient condition for guaranteeing superfluidity. I present then an all-optical defect experiment - where the photon fluid flows against an optically induced obstacle (namely, a local change of refractive index) - designed to measure the drag force cancellation at the fluid/superfluid threshold.
Quantum fluids of light are a photonic counterpart to atomic Bose gases and are attracting increasing interest for probing many-body physics quantum phenomena such as superfluidity. Two different configurations are commonly used: the confined geometry where a nonlinear material is fixed inside an optical cavity and the propagating geometry where the propagation direction plays the role of an effective time for the system. The observation of the dispersion relation for elementary excitations in a photon fluid has proved to be a difficult task in both configurations with few experimental realizations. Here, we propose and implement a general method for measuring the excitations spectrum in a fluid of light, based on a group velocity measurement. We observe a Bogoliubov-like dispersion with a speed of sound scaling as the square root of the fluid density. This Letter demonstrates that a nonlinear system based on an atomic vapor pumped near resonance is a versatile and highly tunable platform to study quantum fluids of light.
Quantum fluids of light are an emerging tool employed in quantum many-body physics. Their amazing properties and versatility allow using them in a wide variety of fields including gravitation, quantum information, and simulation. However the implications of the quantum nature of light in nonlinear optical propagation are still missing many features. We theoretically predict classical spontaneous squeezing of a photon fluid in a nonlocal nonlinear medium. By using the so called Gamow vectors, we show that the quadratures of a coherent state get squeezed and that a maximal squeezing power exists. Our analysis holds true for temporal and spatial optical propagation in a highly nonlocal regime. These results lead to advances in the quantum photon fluids research and may inspire applications in fields like metrology and analogs of quantum gravity.