Spontaneous demagnetization of a dipolar spinor Bose gas at ultralow magnetic field
We study the spinor properties of 𝑆 =3 52Cr condensates, in which dipole-dipole interactions allow changes in magnetization.
arXiv:1103.4819 (2011) / Phys. Rev. Lett. 106, 255303 (2011)
We observe a demagnetization of the Bose-Einstein condensate (BEC) when the magnetic field is quenched below a critical value corresponding to a phase transition between a ferromagnetic and a nonpolarized ground state, which occurs when spin-dependent contact interactions overwhelm the linear Zeeman effect. The critical field is increased when the density is raised by loading the BEC in a deep 2D optical lattice.
The magnetization dynamics is set by dipole-dipole interactions.
