Magneto-optical trapping of neutral atoms in a light-induced effective magnetic field

The ability to produce cold, dense ensembles of neutral atoms is fundamental for many atomic physics experiments and is typically achieved using a magneto-optical trap (MOT). Despite being versatile and robust, the quadrupole magnetic field of a MOT poses difficulties for experiments that are magnetically sensitive. We propose a cold atom trapping method without the use of magnetic fields, replacing a MOT’s magnetic field with additional laser beams that produce an equivalent effective magnetic field using vector light shifts. This effective field induces a spatial dependence to the scattering force from optical molasses beams, trapping the atoms as in a MOT, which we call an “opto-optical trap” (OOT). We perform detailed simulations for Yb-174 to confirm equivalent performance between OOT and MOT. OOTs can be widely applied to commonly laser-cooled species and allow experimental designs that are not possible with anti-Helmholtz coils, such as arrays of small-scale traps or rapid modulation of the effective magnetic field.