The next generation of atomic clocks “ticks” with the frequency of a laser. This is about 100 000 times faster than the microwave frequencies of the caesium clocks which are generating the second at present. These optical clocks are still being assessed, but already now, some are 100 times more accurate than caesium clocks. They will therefore become the future basis for the worldwide definition of the second in the International System of Units (SI). However, these optical clocks must first prove their reliability by being tested repeatedly and by participating in worldwide comparisons.
PTB is one of the global leading institutions and has, up to now, developed an impressive series of different optical clocks – among which are single ion clocks and optical lattice clocks. Now, such high accuracy has also been demonstrated in a new type of clock, which has the potential to measure time and frequency 1000 times more accurately than the caesium clocks that currently realize the SI second. For this purpose, the new ion crystal clock was compared to other optical clocks and achieved a new accuracy record. The results of the measurement campaign, which was carried out as part of the QuantumFrontiers Cluster of Excellence and the Collaborative Research Centre DQ-mat, have been published in the current issue of “Physical Review Letters”.
Read the complete article on the PTB website.
Original publication
H. N. Hausser, J. Keller, T. Nordmann, N. M. Bhatt, J. Kiethe, H. Liu, I. M. Richter, M. von Boehn, J. Rahm et al. :
115In+−172Yb+ Coulomb Crystal Clock with 2.5 × 10−18 Systematic Uncertainty.
Phys. Rev. Lett. 134, 023201.
DOI: https://doi.org/10.1103/PhysRevLett.134.023201
