Dissipationless Vector Drag—Superfluid Spin Hall Effect

Dissipationless flows in single-component superfluids have a significant degree of universality. In He4, the dissipationless mass flow occurs with superfluid velocity determined by gradient phase. However, interacting mixtures, principally new effects appear. this Letter, we demonstrate kind phenomenon arising mixtures bosons optical lattices. We point out that for particular class lattices, condense state where one components' superflow results other component, direction different from either velocities. The free-energy density these systems contains vector product-like interaction velocities, producing noncollinear entrainment. effect represents counterpart Spin Hall effect.