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The Kohn mode for trapped Bose gases within the dielectric formalism

Jürgen Reidl·Gyula Bene·Robert Graham·Péter Szépfalusy
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Abstract

The presence of undamped harmonic center of mass oscillations of a weakly interacting Bose gas in a harmonic trap is demonstrated within the dielectric formalism for a previously introduced finite temperature approximation including exchange. The consistency of the approximation with the Kohn theorem is thereby demonstrated. The Kohn modes are found explicitly, generalizing an earlier zero-temperature result found in the literature. It is shown how the Kohn mode disappears from the single-particle spectrum, while remaining in the density oscillation spectrum, when the temperature increases from below to above the condensation temperature.

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Jürgen Reidl, Gyula Bene, Robert Graham, Péter Szépfalusy. 2000-10-17. The Kohn mode for trapped Bose gases within the dielectric formalism. https://doi.org/10.1103/physreva.63.043605

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