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:1207.1338 · Physical Review Letters

Acoustic Analog to the Dynamical Casimir Effect in a Bose-Einstein Condensate

Jean-Christophe Jaskula, Guthrie B. Partridge, Marie Bonneau, Raphael Lopes, Josselin Ruaudel, Denis Boiron, Christoph Ira Westbrook

Published Nov 26, 2012• 218 citations
arXivHTMLPDF

Abstract

We have modulated the density of a trapped Bose-Einstein condensate by changing the trap stiffness, thereby modulating the speed of sound. We observe the creation of correlated excitations with equal and opposite momenta, and show that for a well-defined modulation frequency, the frequency of the excitations is half that of the trap modulation frequency.

DOI
10.1103/physrevlett.109.220401

Related papers

Density correlations and analog dynamical Casimir emission of Bogoliubov phonons in modulated atomic Bose-Einstein condensates

Iacopo Carusotto, Roberto Balbinot, Alessandro Fabbri +1 more

We present a theory of the density correlations that appear in an atomic Bose-Einstein condensate as a consequence of the emission of correlated pairs of Bogoliubov phonons by a time-dependent atom-atom scattering length. This effect can be considered as a condensed matter analog of the dynamical Casimir effect of quantum field theory. Different regimes as a function of the temporal shape of the modulation are identified and a simple physical picture of the phenomenon is discussed. Analytical expressions for the density correlation function are provided for the most significant limiting cases. This theory is able to explain some unexpected features recently observed in numerical studies of analog Hawking radiation from acoustic black holes.

•Jan 1, 2010•0 citations

Analogs to the dynamical Casimir effect in Bose-Einstein condensates (Orale)

Christoph Ira Westbrook

It is a remarkable prediction of quantum field theory that the vacuum can generate real particles when boundary conditions are suddenly changed. Thus the 'dynamical Casimir effect' results in the spontaneous generation of photon pairs in an empty cavity with nonuniformly accelerating boundaries. Recent advances have permitted the realization of this effect, or analogs to it in a variety of systems, some of which will be discussed at this workshop. Bose Einstein condensates are attractive candidates in which to study acoustic analogs to such phenomena because their low temperatures promise to reveal quantum effects. I will discuss a recent experiment in our group to realize an acoustic analog to the dynamical Casimir effect by modulating the confinement of a Bose-Einstein condensate. We observe correlated pairs of Bogoliubov quanta, both phonon-like and particle-like, are excited by this modulation in a process that formally resembles parametric down conversion. I will discuss our current ideas on how to observe and quantify the degree of entanglement in the excitations we observe.

•Jun 24, 2013•0 citations

Collective Excitations of a Bose-Einstein Condensate in a Magnetic Trap

M.‐O. Mewes, Michael R. Andrews, N. J. van Druten +4 more

Collective excitations of a dilute Bose condensate have been observed. These excitations are analogous to phonons in superfluid helium. Bose condensates were created by evaporatively cooling magnetically trapped sodium atoms. Excitations were induced by a modulation of the trapping potential, and detected as shape oscillations in the freely expanding condensates. The frequencies of the lowest modes agreed well with theoretical predictions based on mean-field theory. Before the onset of Bose-Einstein condensation, we observed sound waves in a dense ultracold gas.

Physical Review Letters•Aug 5, 1996•603 citations

DYNAMICAL BOUNDARIES, CORRELATED EXCITATIONS, AND MODAL ONTOLOGY

Denivaldo Silva, Vidamor Cabannas

This article develops a critical–propositional analysis of J.-C. Jaskula et al.’s 2012 experiment, “Acoustic Analog to the Dynamical Casimir Effect in a Bose-Einstein Condensate,” in systematic dialogue with the foundational and recent corpus of the Theory of Objectivity (TO). Jaskula et al. experimentally modulated the density of a trapped Bose–Einstein condensate by changing the stiffness of its confining potential, thereby modifying the speed of sound and producing correlated Bogoliubov excitations with approximately equal and opposite momenta. Under periodic modulation, the characteristic excitation frequency was observed to be approximately one-half of the imposed modulation frequency, in agreement with pairwise parametric generation. The experiment therefore provides a particularly useful laboratory setting in which boundary conditions, frequency relations, correlation, antecedent physical struc- ture, and the generation of objectively recoverable information appear simultaneously. Jaskula et al. used a condensate containing approximately 105 metastable helium atoms at a temperature of roughly 200 nK and observed opposite-momentum correlations. A comparison with Bragg spectroscopy yielded a factor α = 2.07 ± 0.20, consistent with the interpretation that the imposed modulation generated excitations in pairs (Jaskula et al., 2012). At the same time, the experiment imposes significant limits on any ontological interpretation. The observed excitations were not shown to arise from an unoccupied quasiparticle vacuum. Because of the finite temperature, the relevant modes possessed a non-negligible thermal population. Jaskula et al. further reported neither sub- Poissonian pair-number fluctuations nor a violation of the Cauchy–Schwarz inequality sufficient to demonstrate the nonclassical character of the correlations (Jaskula et al., 2012). The analysis distinguishes the ontological, modal, and empirical levels required by TO. Particular attention is given to the First Absolute Truth, according to which prior to the physical universe there was Nothing, understood not as absolute nonbeing but as an eternal logical and mathematical essence; the Second Absolute Truth, according to which each existing element possesses a magnetic field proper and exclusive to itself that individuates it; and the Fifth Absolute Truth, according to which an element requires relational observation or inclusion within the frequency of at least two other elements for logical existence. In TO this observation is physical and relational, rather than human or conscious observation. The article also articulates Jaskula et al.’s findings with the Fourth, Sixth, and Seventh Absolute Truths, the phenomenic elements, Inducing Effects, the cosmogonic theorem, and the cosmological Eras of TO. The main conclusion is deliberately asymmet ric: Jaskula et al. provide substantial structural compatibility with a relational ontology of boundaries, frequency, composition, and correlation, but they do not empirically establish the primordial Nothing of VA1, the unique individual magnetic field of VA2, the universal existential requirement of VA5, or the TO identity between information and atomic radiation. The experiment is therefore best treated as an operational bridge and as a source of possible differential tests, rather than as direct proof of TO. Keywords: Theory of Objectivity; dynamical Casimir effect; Bose–Einstein condensate; Bogoliubov quasiparticles; quantum vacuum; modal ontology; boundary conditions; correlation; information; analog gravity; Inducing Effects; cosmogenesis.

•Oct 3, 2026•0 citations

Analog quantum simulation of gravitational waves in a Bose-Einstein condensate

Tupac Bravo, Carlos Sabín, Ivette Fuentes

We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms.

arXiv:1406.3572•EPJ Quantum Technology•Jan 4, 2015•15 citations

Propagation of Sound in a Bose-Einstein Condensate

Michael R. Andrews, Dan Stamper-Kurn, H.‐J. Miesner +4 more

Sound propagation has been studied in a magnetically trapped dilute Bose-Einstein condensate. Localized excitations were induced by suddenly modifying the trapping potential using the optical dipole force of a focused laser beam. The resulting propagation of sound was observed using a novel technique, rapid sequencing of nondestructive phase-contrast images. The speed of sound was determined as a function of density and found to be consistent with Bogoliubov theory. This method may generally be used to observe high-lying modes and perhaps second sound.

Physical Review Letters•Jul 28, 1997•444 citations
We have modulated the density of a trapped Bose-Einstein condensate by changing the trap stiffness, thereby modulating the speed of sound. We observe the creation of correlated excitations with equal and opposite momenta, and show that for a well-defined modulation frequency, the frequency of the excitations is half that of the trap modulation frequency.
We present a theory of the density correlations that appear in an atomic Bose-Einstein condensate as a consequence of the emission of correlated pairs of Bogoliubov phonons by a time-dependent atom-atom scattering length. This effect can be considered as a condensed matter analog of the dynamical Casimir effect of quantum field theory. Different regimes as a function of the temporal shape of the modulation are identified and a simple physical picture of the phenomenon is discussed. Analytical expressions for the density correlation function are provided for the most significant limiting cases. This theory is able to explain some unexpected features recently observed in numerical studies of analog Hawking radiation from acoustic black holes.
It is a remarkable prediction of quantum field theory that the vacuum can generate real particles when boundary conditions are suddenly changed. Thus the 'dynamical Casimir effect' results in the spontaneous generation of photon pairs in an empty cavity with nonuniformly accelerating boundaries. Recent advances have permitted the realization of this effect, or analogs to it in a variety of systems, some of which will be discussed at this workshop. Bose Einstein condensates are attractive candidates in which to study acoustic analogs to such phenomena because their low temperatures promise to reveal quantum effects. I will discuss a recent experiment in our group to realize an acoustic analog to the dynamical Casimir effect by modulating the confinement of a Bose-Einstein condensate. We observe correlated pairs of Bogoliubov quanta, both phonon-like and particle-like, are excited by this modulation in a process that formally resembles parametric down conversion. I will discuss our current ideas on how to observe and quantify the degree of entanglement in the excitations we observe.
Collective excitations of a dilute Bose condensate have been observed. These excitations are analogous to phonons in superfluid helium. Bose condensates were created by evaporatively cooling magnetically trapped sodium atoms. Excitations were induced by a modulation of the trapping potential, and detected as shape oscillations in the freely expanding condensates. The frequencies of the lowest modes agreed well with theoretical predictions based on mean-field theory. Before the onset of Bose-Einstein condensation, we observed sound waves in a dense ultracold gas.
This article develops a critical–propositional analysis of J.-C. Jaskula et al.’s 2012 experiment, “Acoustic Analog to the Dynamical Casimir Effect in a Bose-Einstein Condensate,” in systematic dialogue with the foundational and recent corpus of the Theory of Objectivity (TO). Jaskula et al. experimentally modulated the density of a trapped Bose–Einstein condensate by changing the stiffness of its confining potential, thereby modifying the speed of sound and producing correlated Bogoliubov excitations with approximately equal and opposite momenta. Under periodic modulation, the characteristic excitation frequency was observed to be approximately one-half of the imposed modulation frequency, in agreement with pairwise parametric generation. The experiment therefore provides a particularly useful laboratory setting in which boundary conditions, frequency relations, correlation, antecedent physical struc- ture, and the generation of objectively recoverable information appear simultaneously. Jaskula et al. used a condensate containing approximately 105 metastable helium atoms at a temperature of roughly 200 nK and observed opposite-momentum correlations. A comparison with Bragg spectroscopy yielded a factor α = 2.07 ± 0.20, consistent with the interpretation that the imposed modulation generated excitations in pairs (Jaskula et al., 2012). At the same time, the experiment imposes significant limits on any ontological interpretation. The observed excitations were not shown to arise from an unoccupied quasiparticle vacuum. Because of the finite temperature, the relevant modes possessed a non-negligible thermal population. Jaskula et al. further reported neither sub- Poissonian pair-number fluctuations nor a violation of the Cauchy–Schwarz inequality sufficient to demonstrate the nonclassical character of the correlations (Jaskula et al., 2012). The analysis distinguishes the ontological, modal, and empirical levels required by TO. Particular attention is given to the First Absolute Truth, according to which prior to the physical universe there was Nothing, understood not as absolute nonbeing but as an eternal logical and mathematical essence; the Second Absolute Truth, according to which each existing element possesses a magnetic field proper and exclusive to itself that individuates it; and the Fifth Absolute Truth, according to which an element requires relational observation or inclusion within the frequency of at least two other elements for logical existence. In TO this observation is physical and relational, rather than human or conscious observation. The article also articulates Jaskula et al.’s findings with the Fourth, Sixth, and Seventh Absolute Truths, the phenomenic elements, Inducing Effects, the cosmogonic theorem, and the cosmological Eras of TO. The main conclusion is deliberately asymmet ric: Jaskula et al. provide substantial structural compatibility with a relational ontology of boundaries, frequency, composition, and correlation, but they do not empirically establish the primordial Nothing of VA1, the unique individual magnetic field of VA2, the universal existential requirement of VA5, or the TO identity between information and atomic radiation. The experiment is therefore best treated as an operational bridge and as a source of possible differential tests, rather than as direct proof of TO. Keywords: Theory of Objectivity; dynamical Casimir effect; Bose–Einstein condensate; Bogoliubov quasiparticles; quantum vacuum; modal ontology; boundary conditions; correlation; information; analog gravity; Inducing Effects; cosmogenesis.
We show how to vary the physical properties of a Bose-Einstein condensate (BEC) in order to mimic an effective gravitational-wave spacetime. In particular, we focus in the simulation of the recently discovered creation of particles by a real spacetime distortion in box-type traps. We show that, by modulating the speed of sound in the BEC, the phonons experience the effects of a simulated spacetime ripple with experimentally amenable parameters. These results will inform the experimental programme of gravitational wave astronomy with cold atoms.
Sound propagation has been studied in a magnetically trapped dilute Bose-Einstein condensate. Localized excitations were induced by suddenly modifying the trapping potential using the optical dipole force of a focused laser beam. The resulting propagation of sound was observed using a novel technique, rapid sequencing of nondestructive phase-contrast images. The speed of sound was determined as a function of density and found to be consistent with Bogoliubov theory. This method may generally be used to observe high-lying modes and perhaps second sound.