Efficient Two-dimensional Subrecoil Raman Cooling of Atoms in a Tripod Configuration

We present an efficient method for subrecoil cooling of neutral atoms by applying Raman cooling in 2D to a four-level tripod-system. The atoms can be cooled simultaneously in two directions using only three laser beams. We describe the cooling process with a simple model showing that the momentum distribution can be rapidly narrowed to velocity spread down to \(0.1v_\text{rec}\), corresponding to effective temperature equal to \(0.01T_\text{rec}\). This method opens new possibilities for cooling of neutral atoms.