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Updated: May 14, 2026

High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
Measurement of a wavelength of light for which the energy shift for an atom vanishes
William F Holmgren1, Raisa Trubko, Ivan Hromada
1Department of Physics, University of Arizona, Tucson, Arizona 85721, USA.
Abstract:
Light at a magic-zero wavelength causes a zero energy shift for an atom. We measured the longest magic-zero wavelength for ground state potassium atoms to be λ(zero)=768.9712(15) nm, and we show how this measurement provides an improved experimental benchmark for atomic structure calculations. This λ(zero) measurement determines the ratio of the potassium atom D1 and D2 line strengths with record precision. It also demonstrates a new application for atom interferometry, and we discuss how decoherence will fundamentally limit future measurements of magic-zero wavelengths.
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