Spin Rotations in a Bose-Einstein Condensate Driven by Counterflow and Spin-independent Interactions

David C. Spierings, Joseph H. Thywissen, Aephraim M. Steinberg

We observe spin rotations caused by atomic collisions in a non-equilibrium Bose-condensed gas of ${}^{87}$Rb. Reflection from a pseudomagnetic barrier creates counterflow in which fo…