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Title: {sup 87}Rb hyperfine-transition dephasing in mixed buffer-gas systems

Abstract

Elucidating the mechanisms of dephasing in the alkali-metal ground state hyperfine transition has remained an unsatisfactorily resolved problem since the mid-1960s, even though its solution has relevance to next-generation atomic clocks. Recently, however, measurements of electronic spin relaxation in strong magnetic fields have resolved a number of outstanding ambiguities, and the situation has greatly improved. Unfortunately, while these studies have illuminated the processes contributing to hyperfine transition dephasing, they only allow one to infer actual dephasing rates, {gamma}. The direct measurement of dephasing rates remains problematic, primarily as a result of temperature gradient inhomogeneous broadening, which makes it nearly impossible to distinguish systematic from physical effects. Here, we demonstrate that by measuring {gamma} as a function of mole fraction in mixed buffer-gas systems we can isolate temperature gradient effects, thereby allowing a direct comparison between theory and experiment. In the present work, we examine the linewidth of the {sup 87}Rb hyperfine transition in Ar-N{sub 2} mixed buffer-gas systems. We obtain good agreement between theory and experiment so long as we include the full dephasing contribution from RbAr van der Waals molecules: the spin-rotation contribution, {gamma}{sub SR}, and the contribution from the change in {sup 87}Rb hyperfine coupling, {gamma}{sub B}, whichmore » we refer to as the Bouchiat rate. We have been able to measure {gamma}{sub B}, obtaining {gamma}{sub B}=87{+-}6 s{sup -1} for RbAr.« less

Authors:
; ;  [1]
  1. Electronics and Photonics Laboratory, The Aerospace Corporation, P.O. Box 92957, Los Angeles, California 90009 (United States)
Publication Date:
OSTI Identifier:
20982535
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.75.052717; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ALKALI METALS; ARGON; COMPARATIVE EVALUATIONS; COUPLING; GASES; GROUND STATES; HYPERFINE STRUCTURE; MAGNETIC FIELDS; MATHEMATICAL SOLUTIONS; MOLECULES; NITROGEN; RELAXATION; RUBIDIUM 87; SPIN; TEMPERATURE GRADIENTS; VAN DER WAALS FORCES

Citation Formats

Huang, M., Coffer, J. G., and Camparo, J. C. {sup 87}Rb hyperfine-transition dephasing in mixed buffer-gas systems. United States: N. p., 2007. Web. doi:10.1103/PHYSREVA.75.052717.
Huang, M., Coffer, J. G., & Camparo, J. C. {sup 87}Rb hyperfine-transition dephasing in mixed buffer-gas systems. United States. doi:10.1103/PHYSREVA.75.052717.
Huang, M., Coffer, J. G., and Camparo, J. C. Tue . "{sup 87}Rb hyperfine-transition dephasing in mixed buffer-gas systems". United States. doi:10.1103/PHYSREVA.75.052717.
@article{osti_20982535,
title = {{sup 87}Rb hyperfine-transition dephasing in mixed buffer-gas systems},
author = {Huang, M. and Coffer, J. G. and Camparo, J. C.},
abstractNote = {Elucidating the mechanisms of dephasing in the alkali-metal ground state hyperfine transition has remained an unsatisfactorily resolved problem since the mid-1960s, even though its solution has relevance to next-generation atomic clocks. Recently, however, measurements of electronic spin relaxation in strong magnetic fields have resolved a number of outstanding ambiguities, and the situation has greatly improved. Unfortunately, while these studies have illuminated the processes contributing to hyperfine transition dephasing, they only allow one to infer actual dephasing rates, {gamma}. The direct measurement of dephasing rates remains problematic, primarily as a result of temperature gradient inhomogeneous broadening, which makes it nearly impossible to distinguish systematic from physical effects. Here, we demonstrate that by measuring {gamma} as a function of mole fraction in mixed buffer-gas systems we can isolate temperature gradient effects, thereby allowing a direct comparison between theory and experiment. In the present work, we examine the linewidth of the {sup 87}Rb hyperfine transition in Ar-N{sub 2} mixed buffer-gas systems. We obtain good agreement between theory and experiment so long as we include the full dephasing contribution from RbAr van der Waals molecules: the spin-rotation contribution, {gamma}{sub SR}, and the contribution from the change in {sup 87}Rb hyperfine coupling, {gamma}{sub B}, which we refer to as the Bouchiat rate. We have been able to measure {gamma}{sub B}, obtaining {gamma}{sub B}=87{+-}6 s{sup -1} for RbAr.},
doi = {10.1103/PHYSREVA.75.052717},
journal = {Physical Review. A},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}