Optical lattice clocks and quantum metrology

The 'magic wavelength' protocol has made it possible to design atomic clocks based on well-engineered perturbations. Such 'optical lattice clocks' will allow extremely high stability using a large number of atoms and fractional uncertainties of -10(-18) by sharing particular 'magic' wavelengths. This Review covers the experimental realizations of such clocks, the optimal design of optical lattices and recent demonstrations of improved stability for large numbers of atoms. Possible impacts and future applications of optical lattice clocks are also discussed, such as testing the fundamental laws of physics and developing relativistic geodesy.