TY - JOUR

T1 - Importance of nonresonant corrections for the description of atomic spectra

AU - Solovyev, Dmitry

AU - Anikin, Alexei

AU - Zalialiutdinov, Timur

AU - Labzowsky, Leonti N.

PY - 2020/6/28

Y1 - 2020/6/28

N2 - We demonstrate that the present superaccurate measurements of transition processes between atomic states in hydrogen atom reached the limit of accuracy when transition frequency cannot be defined anymore in a unique way. This was predicted earlier and is due to the necessity to include the nonresonant corrections in the description of resonant processes. The observed spectral line profile becomes asymmetric, and it becomes impossible to extract the value of transition frequency from this profile in a unique way. Nonresonant corrections depend on the type of experiment and on the experimental arrangement. However, the line profile itself for any resonant process can be defined with any desired level of accuracy. A popular trend in modern search for atomic frequency standards and atomic clocks is the search for transitions where the nonresonant corrections are negligible. In this paper we present closed expressions for the resonant photon scattering cross sections on an atomic level with dependence on all atomic quantum numbers including fine and hyperfine structure. These expressions are given for different types of experiments with fixing of the incident (outgoing) photon propagation directions and incident (outgoing) photon polarization. Using these expressions we demonstrate that the transition frequencies in particular cases cannot be derived uniquely if the accuracy of measurement reaches the level quoted in A. Beyer {\it et al}, Science {\bf 358}, 79 (2017). The definition of transition frequency suggested in Science {\bf 358}, 79 (2017) may become unique with additional requirements to the process of measurement: the use of the "magic angle" in an experimental arrangement and summation over all possible final states including the hyperfine sublevels. Our interpretation of the results of this experiment is alternative to the interpretation given by Beyer {\it et al}.

AB - We demonstrate that the present superaccurate measurements of transition processes between atomic states in hydrogen atom reached the limit of accuracy when transition frequency cannot be defined anymore in a unique way. This was predicted earlier and is due to the necessity to include the nonresonant corrections in the description of resonant processes. The observed spectral line profile becomes asymmetric, and it becomes impossible to extract the value of transition frequency from this profile in a unique way. Nonresonant corrections depend on the type of experiment and on the experimental arrangement. However, the line profile itself for any resonant process can be defined with any desired level of accuracy. A popular trend in modern search for atomic frequency standards and atomic clocks is the search for transitions where the nonresonant corrections are negligible. In this paper we present closed expressions for the resonant photon scattering cross sections on an atomic level with dependence on all atomic quantum numbers including fine and hyperfine structure. These expressions are given for different types of experiments with fixing of the incident (outgoing) photon propagation directions and incident (outgoing) photon polarization. Using these expressions we demonstrate that the transition frequencies in particular cases cannot be derived uniquely if the accuracy of measurement reaches the level quoted in A. Beyer {\it et al}, Science {\bf 358}, 79 (2017). The definition of transition frequency suggested in Science {\bf 358}, 79 (2017) may become unique with additional requirements to the process of measurement: the use of the "magic angle" in an experimental arrangement and summation over all possible final states including the hyperfine sublevels. Our interpretation of the results of this experiment is alternative to the interpretation given by Beyer {\it et al}.

KW - nonresonant corrections

KW - precise measurements

KW - quantum electrodynamics

KW - quantum interference

KW - transition frequencies

UR - http://www.scopus.com/inward/record.url?scp=85086235653&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/239b431e-1ada-3a35-b8da-46cd3a177c5b/

U2 - 10.1088/1361-6455/ab8b43

DO - 10.1088/1361-6455/ab8b43

M3 - Article

VL - 53

JO - Journal of the European Optical Society Part B: Quantum Optics

JF - Journal of the European Optical Society Part B: Quantum Optics

SN - 0953-4075

IS - 12

M1 - 125002

ER -