New Benchmark for Quantum Electrodynamics: High-Precision Measurement of the g Factor of Boron-like Tin Ions at 0.5 Parts Per Billion

Researchers at the Max Planck Institute for Nuclear Physics in Heidelberg have achieved a new benchmark in quantum electrodynamics (QED) by measuring the g factor of boron-like tin ions with an unprecedented precision of 0.5 parts per billion.

This measurement, conducted using a 118Sn45+ ion stored in the ALPHATRAP ion trap for approximately 40 days, provides critical insights into QED and multiple-electron interactions in heavy systems. By combining this result with previous high-precision measurements of hydrogen-like tin ions, the researchers have demonstrated the potential to independently determine the fine-structure constant, a fundamental quantity governing electromagnetic forces.

Theoretical calculations, which align closely with the experimental findings, further validate the precision of this work. They set a new standard for atomic QED studies and highlight the suitability of highly charged heavy ions as testbeds for exploring complex quantum phenomena.

A New Benchmark for Quantum Electrodynamics in Atoms

The measurement of the g factor in boron-like tin ions has achieved unprecedented precision at 0.5 parts per billion (ppb), marking a significant advancement in quantum electrodynamics (QED) studies. This level of precision, akin to measuring the distance between Cologne and Frankfurt with extreme accuracy, underscores the meticulousness required in such experiments.

This achievement sets a new benchmark for QED by providing insights into multi-electron interactions within heavy systems. The g factor measurement is pivotal as it allows researchers to independently determine the fine-structure constant, a fundamental quantity in physics that characterizes the strength of electromagnetic interactions.

The experiment involved storing 118Sn45+ ions in an ALPHATRAP trap for approximately 40 days, enabling precise measurements by minimizing external disturbances. This extended observation period was crucial for achieving the high precision required for such studies.

Theoretical predictions using ab initio QED methods were consistent with experimental results, demonstrating the reliability of these models. This consistency is vital for validating theoretical frameworks and guiding future research directions.

Looking ahead, boron-like xenon ions (Z=54) are considered promising candidates for further studies due to their potential to minimize nuclear size effects even more effectively than tin ions. Additionally, enhancing theoretical models to match the precision of experimental results remains a critical area of focus.