Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1504.07477

First Measurement of the Atomic Electric Dipole Moment of $^{225}$Ra

Richard H. Parker, Matthew Dietrich, Kalita, M. R., N. Lemke, K. Bailey, Michael Bishof, J. P. Greene, Roy J. Holt, W. Korsch, Zheng‐Tian Lu, Peter Mueller, T.P. O'Connor, Jaideep Taggart Singh

Published Apr 28, 2015• 7 citations
arXivHTMLPDF

Abstract

The radioactive radium-225 ($^{225}$Ra) atom is a favorable case to search for a permanent electric dipole moment (EDM). Due to its strong nuclear octupole deformation and large atomic mass, $^{225}$Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of $^{225}$Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic EDM, reaching an upper limit of $|$$d$($^{225}$Ra)$|$ $

DOI
10.48550/arxiv.1504.07477

Related papers

Measurement of the Electric Dipole Moment of Yb171 Atoms in an Optical Dipole Trap

T. A. Zheng, Yutong Yang, S.-Z. Wang +4 more

The permanent electric dipole moment (EDM) of the $^{171}\mathrm{Yb}$ $(I=1/2)$ atom is measured with atoms held in an optical dipole trap. By enabling a cycling transition that is simultaneously spin-selective and spin-preserving, a quantum nondemolition measurement with a spin-detection efficiency of 50% is realized. A systematic effect due to parity mixing induced by a static $E$ field is observed, and is suppressed by averaging between measurements with optical dipole traps in opposite directions. The coherent spin precession time is found to be much longer than 300 s. The EDM is determined to be $d(^{171}\mathrm{Yb})=\phantom{\rule{0ex}{0ex}}(\ensuremath{-}6.8\ifmmode\pm\else\textpm\fi{}{5.1}_{\text{stat}}\ifmmode\pm\else\textpm\fi{}{1.2}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}27}\text{ }\text{ }e\text{ }\mathrm{cm}$, leading to an upper limit of $|d(^{171}\mathrm{Yb})|<1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}26}\text{ }\text{ }e\text{ }\mathrm{cm}$ (95% C.L.). These measurement techniques can be adapted to search for the EDM of $^{225}\mathrm{Ra}$.

arXiv:2207.08140•Physical Review Letters•Aug 19, 2022•37 citations

CP symmetry test via atomic EDM measurement

Tian Xia

The permanent electric dipole moment (EDM) of atoms, molecules, and elementary particles is predicted in the standard model. While it is too small compared with the experimental measurement sensitivity, it is an important method to search for beyond-standard-model physics via CP violating mechanisms. In this talk, I will focus on the EDM measurement of the 171Yb atoms with atoms held in an optical dipole trap. A quantum nondemolition measurement with a spin-detection efficiency of 50% is realized. A systematic effect due to parity mixing induced by a static E field is observed, and is suppressed by averaging between measurements with optical dipole traps in opposite directions. The coherent spin precession time is found to be much longer than 300 s. The measurement result leads to an upper limit of |d(171Yb)| < 1.5 E−26 e cm (95% C.L.). These measurement techniques can be adapted to search for the EDM of 225Ra.

Optical and Quantum Sensing and Precision Metrology II•Mar 13, 2024•0 citations

Design of an atomic physics experiment to search for the electron electric dipole moment

Melanie Kittle

This thesis describes efforts towards the design and construction of an apparatus to measure the electric dipole moment (edm) of the electron. The current experimental bound on the electron edm, d[subscript e], is |d[subscript e]| ≤ 1.6×10⁻²⁷ e·cm [1]. Our system is designed to be sensitive to an electron dipole moment as small as 10⁻²⁹ e·cm. The experiment will use laser-cooled Cs atoms loaded and captured in optical molasses from a separate 2D MOT cold atom source. The atoms diffusing in the optical molasses will be trapped by two side-by-side standing wave, far-off resonance optical dipole force traps. High voltage electrodes will apply opposite polarity electric fields to the two traps. The signature of an edm would be a first-order electric field shift of the atomic Zeeman levels upon reversal of the electric fields. We have paid special attention to the magnetic noise generated by Johnson noise currents of conductors in the design of this apparatus

•Dec 24, 2005•0 citations

Trapping radioactive Rb82 in an optical dipole trap and evidence of spontaneous spin polarization

D. Feldbaum, H. Wang, Jonathan D. Weinstein +2 more

Optical trapping of selected species of radioactive atoms has great potential in precision measurements for testing fundamental physics such as the electric dipole moment, atomic parity nonconservation, and parity-violating $\ensuremath{\beta}$-decay correlation coefficients. We report on the trapping of ${10}^{4}$ radioactive $^{82}\mathrm{Rb}$ atoms $({t}_{1∕2}=75\phantom{\rule{0.3em}{0ex}}\mathrm{s})$ with a trap lifetime of $\ensuremath{\sim}55\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ in an optical dipole trap. Transfer efficiency from the magneto-optical trap is $\ensuremath{\sim}14%$. We further report evidence of spontaneous spin polarization of the atoms in optical dipole trap loading. These advancements are an important step toward a new generation of precision nuclear-spin--$\ensuremath{\beta}$-emission direction correlation measurements with polarized $^{82}\mathrm{Rb}$ atoms.

arXiv:0708.3826•Physical Review A•Nov 20, 2007•12 citations

Experiments with a laser cooled cloud of atoms

Vasant Natarajan A, Ayan Banerjee, Umakant D. Rapol

We discuss two experiments that can be performed using a cloud of laser-cooled and trapped atoms, namely Bose-Einstein condensation (BEC) and search for a permanent Electric Dipole Moment (EDM). BEC can be observed in Rb atoms in a magnetic trap by using forced evaporative cooling to continuously lower the temperature below the condensation limit. The cloud is cooled by preferentially ejecting the hottest atoms from a magnetic trap. The magnetic trap is loaded with laser-cooled atoms from a magneto-optic trap. The EDM experiment can be performed with a laser-cooled cloud of Yb atoms. The atoms are spin polarized and the precession of the spin is measured in the presence of a strong electric field applied perpendicular to the spin direction. The use of laser-cooled atoms should greatly enhance the sensitivity of the experiment.

•Jan 1, 1999•0 citations

Progress toward a measurement of the electron electrical dipole moment using ultra-cold atoms

Fang Fang

In this thesis, the basic principles of the C, P, T symmetries are introduced and the experiments to measure the electric dipole moment (EDM) are summarized. We propose an experiment to search for the electric dipole moment of the electron using Cs and Rb atoms in 1D optical lattice traps. Our projected sensitivity is 3iN10-30 e-cm with an integration time of 12 hours, which is a 500-fold improvement over the current limit. The potential sources of noise and systematic errors in our designed experiment are analyzed. The preliminary test results for charging small ITO coated electric field plates are given, and the designs of a magnetic shielding system and cancellation coils are also described. We trapped the Cs and Rb atoms in the MOT, and launched Cs atoms up 90 cm from the MOT to the center of the measurement chamber while guided by a resonator enhanced 1D optical lattice trap with transport efficiency up to 50%. The 1064 nm wavelength optical lattice is made in a 2 m long build-up cavity of light, and provides a transverse guide depth of up to 250 ƒÝK. Before they reach the top of their trajectory, the atoms are stopped and cooled by optical molasses, becoming trapped in the 1D lattice. We also demonstrate multiple launches of Cs atoms to the trap.

•Jan 29, 2016•1 citation
First Measurement of the Atomic Electric Dipole Moment of 225^{225}225Ra
The radioactive radium-225 (225^{225}225Ra) atom is a favorable case to search for a permanent electric dipole moment (EDM). Due to its strong nuclear octupole deformation and large atomic mass, 225^{225}225Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of 225^{225}225Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic EDM, reaching an upper limit of |$$d(225^{225}225Ra)∣|∣ $
The permanent electric dipole moment (EDM) of the 171Yb^{171}\mathrm{Yb}171Yb (I=1/2)(I=1/2)(I=1/2) atom is measured with atoms held in an optical dipole trap. By enabling a cycling transition that is simultaneously spin-selective and spin-preserving, a quantum nondemolition measurement with a spin-detection efficiency of 50% is realized. A systematic effect due to parity mixing induced by a static EEE field is observed, and is suppressed by averaging between measurements with optical dipole traps in opposite directions. The coherent spin precession time is found to be much longer than 300 s. The EDM is determined to be $d(^{171}\mathrm{Yb})=\phantom{\rule{0ex}{0ex}}(\ensuremath{-}6.8\ifmmode\pm\else\textpm\fi{}{5.1}_{\text{stat}}\ifmmode\pm\else\textpm\fi{}{1.2}_{\mathrm{syst}})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}27}\text{ }\text{ }e\text{ }\mathrm{cm}$, leading to an upper limit of $|d(^{171}\mathrm{Yb})|<1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}26}\text{ }\text{ }e\text{ }\mathrm{cm}$ (95% C.L.). These measurement techniques can be adapted to search for the EDM of 225Ra^{225}\mathrm{Ra}225Ra.
The permanent electric dipole moment (EDM) of atoms, molecules, and elementary particles is predicted in the standard model. While it is too small compared with the experimental measurement sensitivity, it is an important method to search for beyond-standard-model physics via CP violating mechanisms. In this talk, I will focus on the EDM measurement of the 171Yb atoms with atoms held in an optical dipole trap. A quantum nondemolition measurement with a spin-detection efficiency of 50% is realized. A systematic effect due to parity mixing induced by a static E field is observed, and is suppressed by averaging between measurements with optical dipole traps in opposite directions. The coherent spin precession time is found to be much longer than 300 s. The measurement result leads to an upper limit of |d(171Yb)| < 1.5 E−26 e cm (95% C.L.). These measurement techniques can be adapted to search for the EDM of 225Ra.
This thesis describes efforts towards the design and construction of an apparatus to measure the electric dipole moment (edm) of the electron. The current experimental bound on the electron edm, d[subscript e], is |d[subscript e]| ≤ 1.6×10⁻²⁷ e·cm [1]. Our system is designed to be sensitive to an electron dipole moment as small as 10⁻²⁹ e·cm. The experiment will use laser-cooled Cs atoms loaded and captured in optical molasses from a separate 2D MOT cold atom source. The atoms diffusing in the optical molasses will be trapped by two side-by-side standing wave, far-off resonance optical dipole force traps. High voltage electrodes will apply opposite polarity electric fields to the two traps. The signature of an edm would be a first-order electric field shift of the atomic Zeeman levels upon reversal of the electric fields. We have paid special attention to the magnetic noise generated by Johnson noise currents of conductors in the design of this apparatus
Optical trapping of selected species of radioactive atoms has great potential in precision measurements for testing fundamental physics such as the electric dipole moment, atomic parity nonconservation, and parity-violating $\ensuremath{\beta}$-decay correlation coefficients. We report on the trapping of 104{10}^{4}104 radioactive 82Rb^{82}\mathrm{Rb}82Rb atoms (t1∕2=75s)({t}_{1∕2}=75\phantom{\rule{0.3em}{0ex}}\mathrm{s})(t1∕2​=75s) with a trap lifetime of $\ensuremath{\sim}55\phantom{\rule{0.3em}{0ex}}\mathrm{s}$ in an optical dipole trap. Transfer efficiency from the magneto-optical trap is $\ensuremath{\sim}14%$. We further report evidence of spontaneous spin polarization of the atoms in optical dipole trap loading. These advancements are an important step toward a new generation of precision nuclear-spin--$\ensuremath{\beta}$-emission direction correlation measurements with polarized 82Rb^{82}\mathrm{Rb}82Rb atoms.
We discuss two experiments that can be performed using a cloud of laser-cooled and trapped atoms, namely Bose-Einstein condensation (BEC) and search for a permanent Electric Dipole Moment (EDM). BEC can be observed in Rb atoms in a magnetic trap by using forced evaporative cooling to continuously lower the temperature below the condensation limit. The cloud is cooled by preferentially ejecting the hottest atoms from a magnetic trap. The magnetic trap is loaded with laser-cooled atoms from a magneto-optic trap. The EDM experiment can be performed with a laser-cooled cloud of Yb atoms. The atoms are spin polarized and the precession of the spin is measured in the presence of a strong electric field applied perpendicular to the spin direction. The use of laser-cooled atoms should greatly enhance the sensitivity of the experiment.
In this thesis, the basic principles of the C, P, T symmetries are introduced and the experiments to measure the electric dipole moment (EDM) are summarized. We propose an experiment to search for the electric dipole moment of the electron using Cs and Rb atoms in 1D optical lattice traps. Our projected sensitivity is 3iN10-30 e-cm with an integration time of 12 hours, which is a 500-fold improvement over the current limit. The potential sources of noise and systematic errors in our designed experiment are analyzed. The preliminary test results for charging small ITO coated electric field plates are given, and the designs of a magnetic shielding system and cancellation coils are also described. We trapped the Cs and Rb atoms in the MOT, and launched Cs atoms up 90 cm from the MOT to the center of the measurement chamber while guided by a resonator enhanced 1D optical lattice trap with transport efficiency up to 50%. The 1064 nm wavelength optical lattice is made in a 2 m long build-up cavity of light, and provides a transverse guide depth of up to 250 ƒÝK. Before they reach the top of their trajectory, the atoms are stopped and cooled by optical molasses, becoming trapped in the 1D lattice. We also demonstrate multiple launches of Cs atoms to the trap.