- The paper demonstrates a single-ion 171Yb+ atomic clock utilizing an E3 transition and advanced interrogation techniques to achieve a record low systematic uncertainty.
- The clock achieves a total systematic uncertainty of 3.2 x 10^-18 by minimizing probe light shifts (1.1 x 10^-18) and thermal radiation effects (1.8 x 10^-18).
- This work pushes the boundaries of timekeeping precision, enabling applications in fundamental physics, telecommunications, and navigation, while paving the way for future clock improvements.
Single-Ion Atomic Clock with 3x10-18 Systematic Uncertainty
The paper investigates an advanced optical frequency standard based on the 2S1/2(F=0)→2F7/2(F=3) electric octupole (E3) transition of a single trapped 171Yb+ ion. Leveraging the low sensitivity of this transition to external fields and the large mass of the ion, the paper aims to minimize systematic frequency uncertainties, leading to high precision in atomic clocks.
Key Contributions and Methodologies
The authors introduced an advanced interrogation scheme using Ramsey-type spectroscopy, which is resistant to probe-induced frequency shifts. This method, supported by interleaved single-pulse Rabi spectroscopy, allows for significant reduction of the relative frequency uncertainty due to probe light shifts to 1.1×10−18.
The team determined the static scalar differential polarizability of the E3 transition as 0.888(16)×10−40 J m2/V2, with a dynamic correction factor of η(300 K)=−0.0015(7). With this measurement, the frequency uncertainty due to thermal radiation is reduced to 1.8×10−18.
Results
The single-ion Yb+ atomic clock demonstrates a total systematic uncertainty of 3.2×10−18. This performance represents an improvement over previous optical clocks utilizing different transitions, such as 27Al+ and neutral 87Sr, where residual ion motion and thermal radiation respectively impose higher uncertainties.
The robust methodologies employed—including the hyper-Ramsey spectroscopy (HRS) technique—illustrate the potential of utilizing narrow linewidth transitions to mitigate perturbations that have historically limited clock precision and accuracy.
Implications and Future Directions
This research substantially pushes the boundaries of timekeeping, providing a foundational technology component for ultra-precise time-measurement tools critical to applications requiring tight synchronization, such as global positioning systems (GPS), telecommunications, and fundamental physics experiments.
The high sensitivity of the 171Yb+ 2F7/2 state to variations in fundamental constants enables probing potential violations of Lorentz invariance and exploring the interaction with ultralight scalar dark matter.
Anticipated future advancements may focus on addressing residual motion and further optimizing the trapping methods, which could lead to even lower systematic uncertainty and enhanced clock stability. These improvements could further penetrate applications in fields such as relativistic geodesy and network synchronization.
Overall, this paper demonstrates the forefront of developing atomic clocks. It enhances understanding of systematic perturbation management and provides insights into the subtle interactions between probe light and atomic states.