Coherent Suppression of Tensor Frequency Shifts through Magnetic Field Rotation.

Area of Science:

• Atomic, Molecular, and Optical Physics
• Metrology and Measurement Science
• Quantum Information Science

Background:

• Atomic clocks are crucial for precise timekeeping and scientific research.
• Frequency shifts, particularly tensor shifts, limit the accuracy of atomic clocks.
• Electric quadrupole interactions introduce significant frequency shifts in certain atomic transitions.

Purpose of the Study:

• To introduce a novel scheme for coherently suppressing second-rank tensor frequency shifts in atomic clocks.
• To demonstrate the applicability of the scheme to various atomic clock systems, including the Ytterbium ion.
• To experimentally measure electric quadrupole moments for improved accuracy in atomic clock frequency estimates.

Main Methods:

• Implementing a continuous rotation of an external magnetic field during the free evolution in a Ramsey sequence.
• Applying the developed scheme to the ^{2}S_{1/2}→^{2}D_{3/2} transition of a single trapped ^{171}Yb^{+} ion.
• Measuring excited state electric quadrupole moments for the ^{171}Yb^{+} ion's ^{2}S_{1/2}→^{2}D_{3/2} and ^{2}S_{1/2}→^{2}F_{7/2} transitions.

Main Results:

• Achieved suppression of frequency shifts due to electric quadrupole interaction by over two orders of magnitude.
• Demonstrated the scheme's effectiveness for the ^{171}Yb^{+} ion, particularly for the ^{2}S_{1/2}→^{2}F_{7/2} electric octupole transition.
• Improved measurement uncertainties for electric quadrupole moments by one order of magnitude, obtaining Θ(^{2}D_{3/2})=1.95(1)ea_{0}^{2} and Θ(^{2}F_{7/2})=-0.0297(5)ea_{0}^{2}.

Conclusions:

• The proposed magnetic field rotation scheme effectively suppresses tensor frequency shifts in atomic clocks.
• The method allows for retrieval of unperturbed atomic clock frequencies within a single interrogation cycle.
• Enhanced precision in measuring electric quadrupole moments contributes to more accurate atomic clock performance.