NIST has developed an advanced optical lattice clock using ytterbium (Yb) atoms, achieving unprecedented precision in timekeeping. These clocks operate at optical frequencies (1015 Hz) and use laser-cooled atoms trapped in an optical lattice. NIST’s Yb lattice clocks have set world records in key performance metrics, including frequency stability, systematic uncertainty, and reproducibility, with fractional frequency uncertainties as low as 1×10-18.
The extreme precision of these clocks is used to test fundamental physics and compare different atomic species, contributing to efforts to redefine the SI second. NIST continues to research improvements in quantum control, laser cooling, and systematic effect mitigation to push the limits of optical clock performance further.
Recent research highlights include:
– Subrecoil laser cooling techniques
– Improved interspecies clock comparisons
– Optical clock network frequency ratio measurements
– Coherent optical clock down-conversion
– Optical-Clock-Based Time Scale
– Atomic clock geodesy below the centimeter level
– Faraday-shielded, DC Stark-free optical lattice clocks
– Hyperpolarizability and magic wavelength studies
– Ultrastable optical clocks with cold atom ensembles
– Room-temperature blackbody Stark uncertainty
– Probing many-body interactions in optical lattice clocks
– An atomic clock with 1×10-18 instability
Source: https://www.nist.gov/programs-projects/yb-optical-lattice-clock
Keywords: optical clocks, atomic clocks, frequency stability, optical lattice, clock precision
