We generate spin currents in an Rb87 spin-2 Bose-Einstein condensate by application of a magnetic field gradient. The spin current destroys the spin polarization, leading to a sudden onset of two-body collisions. In addition, the spin coherence, as measured by the fringe contrast using Ramsey interferometry, is reduced drastically but experiences a weak revival due to in-trap oscillations. The spin current can be controlled using periodic π pulses (bang-bang control), producing longer spin-coherence times. Our results show that spin coherence can be maintained even in the presence of spin currents, with applications to quantum sensing in noisy environments.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 2014 Jul 28|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics