Amplification of Local Instabilities in a Bose-Einstein Condensate with Attractive Interactions

TL;DR

This paper investigates how local instabilities in large Bose-Einstein condensates with attractive interactions are amplified, leading to rapid decay primarily through local collapse mechanisms.

Contribution

It demonstrates the amplification of local instabilities via momentum seeding and shows this process dominates the decay of large homogeneous condensates with attractive interactions.

Findings

Local instability amplification observed with momentum seeding

Atoms appear in conjugate momentum states due to momentum conservation

Depletion time scale comparable to global collapse time

Abstract

We study the collapse of large homogeneous Bose-Einstein condensates due to intrinsic attractive interactions. We observe the amplification of a local instability by seeding a momentum state $\bf{p}$ and suddenly switching the scattering length negative via a Feshbach resonance. As required by momentum conservation, we also observe the appearance of atoms in the conjugate momentum state. The time scale for this depletion process is found to be comparable to that for global collapse, implying that this process will be the primary decay channel for large homogeneous condensates.