We characterize fluctuations in atom number and spin populations in F = 1 sodium spinor condensates. The time evolution of the population fluctuations shows a maximum. We interpret this as evidence of a dissipation-driven separatrix crossing in phase space. For a given initial state, the critical time to the separatrix crossing is found to depend exponentially on the magnetic field and linearly on condensate density. This crossing is confirmed by tracking the energy of the spinor condensate as well as by Faraday rotation spectroscopy. We introduce a phenomenological model to quantitatively describe the observed energy dissipation with a single parameter.
Citation: Physical Review Letters
Pub Type: Journals
atom number fluctuations, energy dissipation, phase-space dynamics, separatrix crossing, spinor condensate