Precision Isotope Shift Measurements in Calcium Ions Using Quantum Logic Detection Schemes

Area of Science:

• Atomic Physics
• Quantum Spectroscopy
• Ion Trapping

Background:

• Precise atomic spectroscopy is crucial for fundamental physics and metrology.
• Measuring transitions in single trapped ions requires sensitive techniques, especially for nonclosed transitions.

Purpose of the Study:

• To demonstrate an efficient, high-precision optical spectroscopy technique for single trapped ions with nonclosed transitions.
• To perform the first high-precision absolute frequency measurement of the 2D(3/2)→2P(1/2) transition in calcium.
• To determine isotope shifts and extract nuclear properties.

Main Methods:

• Utilizing a double-shelving technique to amplify single-photon absorption.
• Employing a cotrapped cooling ion of a different species for signal amplification.
• Extending the photon recoil spectroscopy technique for high-resolution measurements.

Main Results:

• Achieved high-precision absolute frequency measurement of the 2D(3/2)→2P(1/2) transition in calcium (346,000,234,867(96) kHz).
• Determined isotope shifts for 42Ca+, 44Ca+, and 48Ca+ relative to 40Ca+ with <100 kHz accuracy.
• Extracted improved field and mass shift constants and changes in mean square nuclear charge radii.

Conclusions:

• The developed spectroscopy technique is efficient and highly precise for single trapped ions with nonclosed transitions.
• The measurements provide valuable data for atomic structure calculations and nuclear physics.
• This method opens new avenues for high-resolution spectroscopy of atomic ions.