© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:2202.10835 · Physical Review A

Density correlations from analog Hawking radiation in the presence of atom losses

Yash Palan, Sebastian Wüster

Published Nov 18, 2022• 3 citations

Abstract

The sonic analog of Hawking radiation can now be experimentally recreated in Bose-Einstein condensates that contain an acoustic black hole. In these experiments the signal strength and approximate analog Hawking temperature increase for denser condensates, which however also suffer increased atom losses from inelastic collisions. To determine how these affect analog Hawking radiation, we numerically simulate creation of the latter in a Bose-Einstein condensate in the presence of atomic losses, including nonunitary quantum field dynamics using the truncated Wigner approximation. In particular we explore modifications of density-density correlations through which the radiation has been analyzed so far. We find no evidence that losses directly alter the basic picture of the analog Hawking effect; instead all consequences that we find are indirect: Losses increase the contrast of the correlation signal, which we attribute to condensate heating by the losses, in turn leading to a component of stimulated radiation in addition to the spontaneous one. Other indirect consequences are the modification of the white-hole instability pattern and a change of slope of the Hawking tongue.

DOI: 10.1103/physreva.106.053317

Related papers

Numerical observation of Hawking radiation from acoustic black holes in atomic Bose–Einstein condensates

Iacopo Carusotto, Serena Fagnocchi, Alessio Recati +2 more

We report numerical evidence of Hawking emission of Bogoliubov phonons from a sonic horizon in a flowing one-dimensional atomic Bose–Einstein condensate. The presence of Hawking radiation is revealed from peculiar long-range patterns in the density–density correlation function of the gas. Quantitative agreement between our fully microscopic calculations and the prediction of analog models is obtained in the hydrodynamic limit. New features are predicted and the robustness of the Hawking signal against a finite temperature discussed.

arXiv:0803.0507•New Journal of Physics•Oct 2, 2008•290 citations

Ramp-up of Hawking Radiation in Bose-Einstein-Condensate Analog Black Holes

Alessandro Fabbri, Roberto Balbinot

Inspired by a recent experiment by Steinhauer and co-workers, we present a simple model which describes the formation of an acoustic black hole in a Bose-Einstein condensate, allowing an analytical computation of the evolution in time of the corresponding density-density correlator. We show the emergence of analog Hawking radiation out of a "quantum atmosphere" region significantly displaced from the horizon. This is quantitatively studied both at T=0 and even in the presence of an initial temperature T, as is always the case experimentally.

arXiv:2005.04443•Physical Review Letters•Mar 18, 2021•21 citations

Bogoliubov theory of acoustic Hawking radiation in Bose-Einstein condensates

Alessio Recati, Nicolas Pavloff, Iacopo Carusotto

We apply the microscopic Bogoliubov theory of dilute Bose-Einstein condensates to analyze quantum and thermal fluctuations in a flowing atomic condensate in the presence of a sonic horizon. For the simplest case of a step-like horizon, closed-form analytical expressions are found for the spectral distribution of the analog Hawking radiation and for the density correlation function. The peculiar long-distance density correlations that appear as a consequence of the Hawking emission features turns out to be reinforced by a finite initial temperature of the condensate. The analytical results are in good quantitative agreement with first principle numerical calculations.

arXiv:0907.4305•Physical Review A•Oct 7, 2009•169 citations

Observing Hawking radiation in Bose-Einstein condensates via correlation measurements

Alessandro Fabbri

Observing quantum particle creation by black holes (Hawking radiation) in the astrophysical context is, in ordinary situations, hopeless. Nevertheless the Hawking effect, which depends only on kinematical properties of wave propagation in the presence of horizons, is present also in nongravitational contexts, for instance in stationary fluids undergoing supersonic flow. We present results on how to observe the analog Hawking radiation in Bose-Einstein condensates by a direct measurement of the density correlations due to the phonon pairs (Hawking quanta-partner) created by the acoustic horizon.

arXiv:1212.5392•Dec 21, 2012•0 citations

Acoustic white holes in flowing atomic Bose–Einstein condensates

Carlos Mayoral, Alessio Recati, Alessandro Fabbri +3 more

We study acoustic white holes in a steadily flowing atomic Bose–Einstein condensate. A white hole configuration is obtained when the flow velocity goes from a super-sonic value in the upstream region to a sub-sonic one in the downstream region. The scattering of phonon wavepackets on a white hole horizon is numerically studied in terms of the Gross–Pitaevskii equation of mean-field theory: dynamical stability of the acoustic white hole is found, as well as a signature of a nonlinear back-action of the incident phonon wavepacket onto the horizon. The correlation pattern of density fluctuations is numerically studied by means of the truncated-Wigner method, which includes quantum fluctuations. Signatures of the white hole radiation of correlated phonon pairs by the horizon are characterized; analogies and differences with Hawking radiation from acoustic black holes are discussed. In particular, a short wavelength feature is identified in the density correlation function, whose amplitude steadily grows in time since the formation of the horizon. The numerical observations are quantitatively interpreted by means of an analytical Bogoliubov theory of quantum fluctuations for a white hole configuration within the step-like horizon approximation.

arXiv:1009.6196•New Journal of Physics•Feb 4, 2011•71 citations

Nonlocal density correlations as a signature of Hawking radiation from acoustic black holes

Roberto Balbinot, Alessandro Fabbri, Serena Fagnocchi +2 more

We have used the analogy between gravitational systems and nonhomogeneous fluid flows to calculate the density-density correlation function of an atomic Bose-Einstein condensate in the presence of an acoustic black hole. The emission of correlated pairs of phonons by Hawking-like process results into a peculiar long-range density correlation. Quantitative estimations of the effect are provided for realistic experimental configurations.

arXiv:0711.4520•Physical Review A•Aug 19, 2008•207 citations

The sonic analog of Hawking radiation can now be experimentally recreated in Bose-Einstein condensates that contain an acoustic black hole. In these experiments the signal strength and approximate analog Hawking temperature increase for denser condensates, which however also suffer increased atom losses from inelastic collisions. To determine how these affect analog Hawking radiation, we numerically simulate creation of the latter in a Bose-Einstein condensate in the presence of atomic losses, including nonunitary quantum field dynamics using the truncated Wigner approximation. In particular we explore modifications of density-density correlations through which the radiation has been analyzed so far. We find no evidence that losses directly alter the basic picture of the analog Hawking effect; instead all consequences that we find are indirect: Losses increase the contrast of the correlation signal, which we attribute to condensate heating by the losses, in turn leading to a component of stimulated radiation in addition to the spontaneous one. Other indirect consequences are the modification of the white-hole instability pattern and a change of slope of the Hawking tongue.

We report numerical evidence of Hawking emission of Bogoliubov phonons from a sonic horizon in a flowing one-dimensional atomic Bose–Einstein condensate. The presence of Hawking radiation is revealed from peculiar long-range patterns in the density–density correlation function of the gas. Quantitative agreement between our fully microscopic calculations and the prediction of analog models is obtained in the hydrodynamic limit. New features are predicted and the robustness of the Hawking signal against a finite temperature discussed.

Inspired by a recent experiment by Steinhauer and co-workers, we present a simple model which describes the formation of an acoustic black hole in a Bose-Einstein condensate, allowing an analytical computation of the evolution in time of the corresponding density-density correlator. We show the emergence of analog Hawking radiation out of a "quantum atmosphere" region significantly displaced from the horizon. This is quantitatively studied both at T=0 and even in the presence of an initial temperature T, as is always the case experimentally.

We apply the microscopic Bogoliubov theory of dilute Bose-Einstein condensates to analyze quantum and thermal fluctuations in a flowing atomic condensate in the presence of a sonic horizon. For the simplest case of a step-like horizon, closed-form analytical expressions are found for the spectral distribution of the analog Hawking radiation and for the density correlation function. The peculiar long-distance density correlations that appear as a consequence of the Hawking emission features turns out to be reinforced by a finite initial temperature of the condensate. The analytical results are in good quantitative agreement with first principle numerical calculations.

Observing quantum particle creation by black holes (Hawking radiation) in the astrophysical context is, in ordinary situations, hopeless. Nevertheless the Hawking effect, which depends only on kinematical properties of wave propagation in the presence of horizons, is present also in nongravitational contexts, for instance in stationary fluids undergoing supersonic flow. We present results on how to observe the analog Hawking radiation in Bose-Einstein condensates by a direct measurement of the density correlations due to the phonon pairs (Hawking quanta-partner) created by the acoustic horizon.

We study acoustic white holes in a steadily flowing atomic Bose–Einstein condensate. A white hole configuration is obtained when the flow velocity goes from a super-sonic value in the upstream region to a sub-sonic one in the downstream region. The scattering of phonon wavepackets on a white hole horizon is numerically studied in terms of the Gross–Pitaevskii equation of mean-field theory: dynamical stability of the acoustic white hole is found, as well as a signature of a nonlinear back-action of the incident phonon wavepacket onto the horizon. The correlation pattern of density fluctuations is numerically studied by means of the truncated-Wigner method, which includes quantum fluctuations. Signatures of the white hole radiation of correlated phonon pairs by the horizon are characterized; analogies and differences with Hawking radiation from acoustic black holes are discussed. In particular, a short wavelength feature is identified in the density correlation function, whose amplitude steadily grows in time since the formation of the horizon. The numerical observations are quantitatively interpreted by means of an analytical Bogoliubov theory of quantum fluctuations for a white hole configuration within the step-like horizon approximation.