Measurement of the electric quadrupole amplitude in atomic thallium $6P_{1/2}\rightarrow6P_{3/2}$ transition using electromagnetically induced transparency

TL;DR

This paper measures the electric quadrupole to magnetic dipole transition amplitude ratio in atomic thallium using electromagnetically induced transparency, providing new experimental data to inform atomic structure theories and parity non-conservation studies.

Contribution

First measurement of the electric quadrupole to magnetic dipole amplitude ratio in atomic thallium's $6P_{1/2} ightarrow6P_{3/2}$ transition using EIT.

Findings

Measured $ ext{χ}_{205} = 0.2550(20)(7)$ for $^{205}$Tl.

Measured $ ext{χ}_{203} = 0.2532(73)(7)$ for $^{203}$Tl.

Provides experimental data relevant for atomic structure calculations and PNC research.

Abstract

We report a measurement of the transition amplitude ratio $\chi$ of an electric quadrupole ($E2$) to a magnetic dipole ($M1$) of the $6P_{1/2}\rightarrow6P_{3/2}$ transition in atomic thallium. We utilized the electromagnetically induced transparency (EIT) mechanism and the sideband-bridging technique to resolve the isotopic transitions and their hyperfine manifold. Our measurement gave $\chi_{205}~=~0.2550(20)(7)$ for $^{205}$Tl, and $\chi_{203}=0.2532(73)(7)$ for $^{203}$Tl, which was measured for the first time. Our result provides a reference point for the theoretical calculation of atomic structure and new input for the long dispute on the atomic thallium PNC measurements.