Spin mixing and protection of ferromagnetism in a spinor dipolar condensate
We study spin mixing dynamics in a chromium dipolar Bose-Einstein condensate, after tilting the atomic spins by an angle 𝜃 with respect to the magnetic field.
arXiv:1705.08358 (2017) / Phys. Rev. A 97, 023610 (2018)
Spin mixing is triggered by dipolar coupling, but, once dynamics has started, it is mostly driven by contact interactions. For the particular case 𝜃=𝜋/2, an external spin-orbit coupling term induced by a magnetic gradient is required to enable the dynamics. Then the initial ferromagnetic character of the gas is locally preserved, an unexpected feature that we attribute to large spin-dependent contact interactions.
