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How to measure the Bogoliubov quasiparticle amplitudes in a trapped condensate

A. Brunello·F. Dalfovo·L. Pitaevskii·S. Stringari
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Abstract

We propose an experiment, based on two consecutive Bragg pulses, to measure the momentum distribution of quasiparticle excitations in a trapped Bose gas at low temperature. With the first pulse one generates a bunch of excitations carrying momentum $q$, whose Doppler line is measured by the second pulse. We show that this experiment can provide direct access to the amplitudes $u_{q}$ and $v_{q}$ characterizing the Bogoliubov transformations from particles to quasiparticles. We simulate the behavior of the nonuniform gas by numerically solving the time dependent Gross-Pitaevskii equation.

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A. Brunello, F. Dalfovo, L. Pitaevskii, S. Stringari. 2000-07-07. How to measure the Bogoliubov quasiparticle amplitudes in a trapped condensate. https://doi.org/10.1103/physrevlett.85.4422

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