Reconfigurable atom chip on a transparent ferrite-garnet film

We introduce a new choice of material for the creation of microscopicmagneticpotentials for the trapping and guiding of ultracold neutral atoms.The potentials are created above a ferrimagnetic, transparent (BiYTmGd)₃(FeGa)₅O₁₂film by patterning the magnetic-domain structure in the film witha magneto-optical recording method. Patterns with linewidth down to2 μm have been achieved, enabling trap frequencies of the orderof 100 kHz for ⁸⁷Rb atoms in the state |F=1, m_F=-1〉.The main advantages of the material are: 1) magnetic-field noiseis suppressed due to the dielectricity of the material and the absenceof electric currents, 2) trapped atoms can be addressed opticallythrough the transparent film, and 3) the film can be repatterned,which enables different experiments with the same component.