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

• Published in: The European physical journal. D, Atomic, molecular, and optical physics Vol. 56; no. 3; pp. 391 - 404
• Main Authors: Carusotto, I., Balbinot, R., Fabbri, A., Recati, A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-02-2010; EDP Sciences
• Subjects: Applications of Nonlinear Dynamics and Chaos Theory; Atomic; Classical and quantum physics: mechanics and fields; Cold Matter and Quantum Gases; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Lattice dynamics; Matter waves; Molecular; Optical and Plasma Physics; Phonons and vibrations in crystal lattices; Physical Chemistry; Physics; Physics and Astronomy; Quantum Information Technology; Quantum Physics; Spectroscopy/Spectrometry; Spintronics; Thick Black Line; Fringe Pattern; Slow Ramp; Density Correlation Function; Density Correlation; Atom-atom collisions; Casimir effect; Dynamic properties; Correlation functions; Atomic condensates; Quantum field theory; Bose-Einstein condensation; Scattering lengths
• ISSN: 1434-6060; 1434-6079
• DOI: 10.1140/epjd/e2009-00314-3

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.