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 , whose Doppler line is measured by the second pulse. We show that this experiment can provide direct access to the amplitudes and 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.
- Received 7 July 2000
DOI:https://doi.org/10.1103/PhysRevLett.85.4422
©2000 American Physical Society