Stable Spin Precession at One Half of Equilibrium Magnetization in Superfluid 3He-B

New modes of spin precession have been observed in superfluid ³He-B with a precessing magnetization M = pM_eq, where p = 1, 12, and ~0. These dynamic order parameter states are the first examples of stable precession with a magnetization different from the equilibrium value M_eq. The p = 12 mode is the second example of a phase-coherent state of a spin superfluid. The new states can be excited close to T_c in the range 1-T/T_c<~0.02 where dissipation is low and the energy barriers between the different local minima of the spin-orbit energy are small.