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arXiv · 1402.1196

Lifetime of Single-Particle Excitations in a Dilute Bose-Einstein Condensate at Zero Temperature

Kazumasa Tsutsui·Takafumi Kita
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Abstract

We study the lifetime of single-particle excitations in a dilute homogeneous Bose-Einstein condensate at zero temperature based on a self-consistent perturbation expansion of satisfying Goldstone's theorem and conservation laws simultaneously.It is shown that every excitation for each momentum ${\bf p}$ should have a finite lifetime proportional to the inverse $a^{-1}$ of the $s$-wave scattering length $a$, instead of $a^{-2}$ for the normal state, due to a new class of Feynman diagrams for the self-energy that emerges upon condensation. We calculate the lifetime as a function of $|{\bf p}|$ approximately.

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Kazumasa Tsutsui, Takafumi Kita. 2014-02-05. Lifetime of Single-Particle Excitations in a Dilute Bose-Einstein Condensate at Zero Temperature. https://doi.org/10.7566/jpsj.83.033001

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