© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Bulletin of the American Physical Society

Laser-microwave double resonance frequency standard using {sup 199}Hg{sup +} ions in a cryogenic linear trap

Martin E. Poitzsch, Jonas Bergquist, W. M. Itano, David J. Wineland

Published May 1, 1993• 0 citations

Abstract

We have previously reported experiments using a linear rf trap to store laser-cooled {sup 199}Hg{sup +} ions. Trapping multiple ions increases the signal-to-noise ratio; yet all ions have equally low second-order Doppler shifts if they are confined along the nodal center line of a linear trap. In such an environment, the 40.5 GHz ground-state hyperfine transition in {sup 199}Hg{sup +} is a candidate for an extremely accurate and stable microwave frequency standard. Our redesigned apparatus will operate at cryogenic temperatures to provide very low background gas pressure (resulting in longer ion storage times and immunity from background pressure shifts) and superconductive shielding against stray magnetic fields. We shall discuss progress on this frequency standard and applications of our apparatus to new cooling and squeezing techniques.

Related papers

Progress toward a cryogenic /sup 199/Hg/sup +/ ion frequency standard

Martin E. Poitzsch, Jonas Bergquist, Wayne M. Itano +1 more

We have observed linear "crystals" of up to tens of laser-cooled /sup 199/Hg/sup +/ ions in a new cryogenic linear rf ion trap that operates at liquid helium temperature and is designed for use as a prototype 40.5 GHz frequency standard with high accuracy and stability.>

Conference on Precision Electromagnetic Measurements•Dec 17, 2002•0 citations

High-accuracy frequency standards using laser-cooled Hg+ ions

Dana J. Berkeland, J.D. Miller, Brent C. Young +3 more

We discuss frequency standards based on laser-cooled 199Hg+ ions confined in cryogenic rf traps. In one experiment, the frequency of a microwave source is served to the ions' ground-state hyperfine transition at 40.5 GHz. For seven ions and a Ramsey free precession time of 100 s, the fractional frequency stability is 3.3 (2) X 10-13 (tau) -1/2 for measurement times (tau) < 2 h. The ground-state hyperfine interval is measured to be 40 507 347 996.841 59 (14) (41) Hz, where the first number in parentheses is the uncertainty due to statistics and systematic errors, and the second is the uncertainty in the frequency of the time scale to which the standard is compared. In a second experiment under development, a strong-binding cryogenic trap will confine a single ion used for an optical frequency standard based on a narrow electric quadrupole transition at 282 nm. The bandwidth of the laser used to drive this transition is less than 10 Hz at 563 nm.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 15, 1998•1 citation

Progress on a cryogenic linear trap for /sup 199/Hg/sup +/ ions

Martin E. Poitzsch, T.J.C. Bergquist, Wayne M. Itano +1 more

We have observed linear "crystals" of up to tens of laser-cooled /sup 199/Hg/sup +/ ions in a new cryogenic linear rf ion trap that operates at liquid helium temperature and is designed for use as a prototype 40.5 GHz frequency standard with high accuracy and stability.>

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Dec 17, 2002•1 citation

A cryogenic linear ion trap for /sup 199/Hg/sup +/ frequency standards

J.D. Miller, Dana J. Berkeland, Flávio C. Cruz +3 more

A cryogenic linear rf trap has been constructed to study the accuracy of a clock based on laser cooled /sup 199/Hg/sup +/. Crystals of tens of ions have been observed. The residual micromotion of the ions has been minimized and Ramsey interrogation periods of 100 s have been demonstrated for the 40.5 GHz transition. Systematic shifts to the clock transition due to magnetic field fluctuations as well as heating of the ions during the clock cycle have been evaluated. This system should eventually provide a frequency standard of high precision and accuracy.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Dec 23, 2002•0 citations

A cryogenic linear ion trap for /sup 199/Hg/sup +/ frequency standards

J.D. Miller, M.E. Poitzsch, Flávio C. Cruz +4 more

A cryogenic linear rf trap has been constructed to study the accuracy of a clock based on laser cooled /sup 199/Hg/sup +/. Crystals of tens of ions have been observed. The residual micromotion of the ions has been minimized and Ramsey interrogation periods of 25 s have been demonstrated for the 40.5 GHz transition. This system should eventually provide a frequency standard of high precision and accuracy. We report on the development of compact, efficient, solid-state sources at 194 nm and 282 nm for laser cooling of /sup 199/Hg/sup +/ and investigation of the /sup 2/S/sub 1/2//spl rarr//sup 2/D/sub 5/2/ quadrupole transition of interest for an optical frequency standard.

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Nov 19, 2002•0 citations

Progress at CSIRO Australia towards a microwave frequency standard based on trapped, laser-cooled /sup 171/Yb/sup +/ ions

Peter Fisk, M.A. Lawn, C. Coles

The authors report preliminary results of precision microwave-optical double resonance spectroscopy on buffer gas cooled /sup 171/Yb/sup +/ ions confined in a linear Paul trap as a microwave frequency standard at 12.6 GHz. They also report laser cooling of trapped /sup 171/Yb/sup +/ ions. Temperatures below 1 K have been achieved, and evidence for a phase transition to a crystal-like state has been found. This temperature is sufficiently low to reduce the fractional second-order Doppler shift of the microwave resonance to below 10/sup -14/.>

Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium (EFTF/IFCS)•Dec 30, 2002•1 citation

We have previously reported experiments using a linear rf trap to store laser-cooled {sup 199}Hg{sup +} ions. Trapping multiple ions increases the signal-to-noise ratio; yet all ions have equally low second-order Doppler shifts if they are confined along the nodal center line of a linear trap. In such an environment, the 40.5 GHz ground-state hyperfine transition in {sup 199}Hg{sup +} is a candidate for an extremely accurate and stable microwave frequency standard. Our redesigned apparatus will operate at cryogenic temperatures to provide very low background gas pressure (resulting in longer ion storage times and immunity from background pressure shifts) and superconductive shielding against stray magnetic fields. We shall discuss progress on this frequency standard and applications of our apparatus to new cooling and squeezing techniques.

We discuss frequency standards based on laser-cooled 199Hg+ ions confined in cryogenic rf traps. In one experiment, the frequency of a microwave source is served to the ions' ground-state hyperfine transition at 40.5 GHz. For seven ions and a Ramsey free precession time of 100 s, the fractional frequency stability is 3.3 (2) X 10-13 (tau) -1/2 for measurement times (tau) < 2 h. The ground-state hyperfine interval is measured to be 40 507 347 996.841 59 (14) (41) Hz, where the first number in parentheses is the uncertainty due to statistics and systematic errors, and the second is the uncertainty in the frequency of the time scale to which the standard is compared. In a second experiment under development, a strong-binding cryogenic trap will confine a single ion used for an optical frequency standard based on a narrow electric quadrupole transition at 282 nm. The bandwidth of the laser used to drive this transition is less than 10 Hz at 563 nm.

A cryogenic linear rf trap has been constructed to study the accuracy of a clock based on laser cooled /sup 199/Hg/sup +/. Crystals of tens of ions have been observed. The residual micromotion of the ions has been minimized and Ramsey interrogation periods of 100 s have been demonstrated for the 40.5 GHz transition. Systematic shifts to the clock transition due to magnetic field fluctuations as well as heating of the ions during the clock cycle have been evaluated. This system should eventually provide a frequency standard of high precision and accuracy.

A cryogenic linear rf trap has been constructed to study the accuracy of a clock based on laser cooled /sup 199/Hg/sup +/. Crystals of tens of ions have been observed. The residual micromotion of the ions has been minimized and Ramsey interrogation periods of 25 s have been demonstrated for the 40.5 GHz transition. This system should eventually provide a frequency standard of high precision and accuracy. We report on the development of compact, efficient, solid-state sources at 194 nm and 282 nm for laser cooling of /sup 199/Hg/sup +/ and investigation of the /sup 2/S/sub 1/2//spl rarr//sup 2/D/sub 5/2/ quadrupole transition of interest for an optical frequency standard.

The authors report preliminary results of precision microwave-optical double resonance spectroscopy on buffer gas cooled /sup 171/Yb/sup +/ ions confined in a linear Paul trap as a microwave frequency standard at 12.6 GHz. They also report laser cooling of trapped /sup 171/Yb/sup +/ ions. Temperatures below 1 K have been achieved, and evidence for a phase transition to a crystal-like state has been found. This temperature is sufficiently low to reduce the fractional second-order Doppler shift of the microwave resonance to below 10/sup -14/.>