Optical lattice clocks and frequency comparisons

To date, optical clocks based on singly trapped ions and ultracold neutral atoms trapped in the Stark-shift-free optical lattices are regarded as promising candidates for future atomic clocks. Since 2006, “optical lattice clocks” have been evaluated close to the Cs clocks´ uncertainty limit internationally. One of the essential experimental challenges in the development of “optical lattice clocks” is to find out the better lattice geometries as well as interrogated atom species (including their quantum statistics) that bring out the potential performance of the clock scheme, taking into account the collisional frequency shift, the Black body radiation (BBR) shift, the atomic multipolar and hyperpolarizability effects.