Grating Magneto Optical Trap

A method for trapping a cold-atom cloud, the method comprising providing a three-dimensional grating magneto optical trap (3D GMOT), comprising:

• providing a first, single input light beam having its direction along a first axis, an area along a second and third axis that are both normal to the first axis, and a substantially flat input light beam intensity profile extending across its area;
• providing a circular, diffraction-grating surface positioned normal to the first axis and extending along the second and third axis;
• the circular, diffraction-grating surface having closely adjacent grooves arranged concentrically around a gap formed in the center of the circular, diffraction-grating surface;
• the circular, diffraction-grating surface configured to:
• diffract first-order light beams that intersect within an intersection region that lies directly above the gap, and
• suppresses reflections and diffractions of all other orders;
• and
• providing a quadrupole magnetic field with its magnitude being zero within the intersection region;
• wherein the 3D GMOT is configured to trap the cold-atom cloud within the intersection region.