Spinor condensates with a laser-induced quadratic Zeeman effect

We show that an effective quadratic Zeeman effect for trapped atoms can be generated by proper laserconfigurations and, in particular, by the dipole trap itself. The induced quadratic Zeeman effect leads to a richground-state phase diagram, e.g., for a degenerate 52Cr gas, can be used to induce topological defects bycontrollably quenching across transitions between phases of different symmetries, allows for the observabilityof the Einstein-de Haas effect for relatively large magnetic fields, and may be employed to create S=1/2systems with spinor dynamics. Similar ideas could be explored in other atomic species opening an excitingnew control tool in spinor systems.