# Cooling phonon modes of a Bose condensate with uniform few body losses

### Submission summary

 As Contributors: Isabelle Bouchoule Arxiv Link: https://arxiv.org/abs/1806.08759v4 (pdf) Date accepted: 2018-10-26 Date submitted: 2018-10-25 02:00 Submitted by: Bouchoule, Isabelle Submitted to: SciPost Physics Academic field: Physics Specialties: Condensed Matter Physics - Theory Quantum Physics Approach: Theoretical

### Abstract

We present a general analysis of the cooling produced by losses on condensates or quasi-condensates. We study how the occupations of the collective phonon modes evolve in time, assuming that the loss process is slow enough so that each mode adiabatically follows the decrease of the mean density. The theory is valid for any loss process whose rate is proportional to the $j$th power of the density, but otherwise spatially uniform. We cover both homogeneous gases and systems confined in a smooth potential. For a low-dimensional gas, we can take into account the modified equation of state due to the broadening of the cloud width along the tightly confined directions, which occurs for large interactions. We find that at large times, the temperature decreases proportionally to the energy scale $mc^2$, where $m$ is the mass of the particles and $c$ the sound velocity. We compute the asymptotic ratio of these two quantities for different limiting cases: a homogeneous gas in any dimension and a one-dimensional gas in a harmonic trap.

### Ontology / Topics

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Published as SciPost Phys. 5, 043 (2018)

Dear editor,

Please find here a new version of our paper that we re-submit to Scipost.

Best regards,
The authors.

### List of changes

According to the second referee comments, we put more emphasis on the fact that results of this paper have been successfully tested in a recent experimental paper of M. Schemmer and I. Bouchoule, where the effect of 3-body losses on a 1D Bose gas is investigated (ref [9] of the manuscript). More precisely, we added a sentence at the end of the introduction and a sentence after Eq. 23-27.