Measurement of Linear Stark Interference in $^{199}\mathrm{Hg}$

Measurement of Linear Stark Interference in ${}^{199}{Hg}$

T. H. Loftus, M. D. Swallows, W. C. Griffith, M. V. Romalis, B. R. Heckel, and E. N. Fortson

Phys. Rev. Lett. 106, 253002 – Published 24 June 2011

Abstract

We present measurements of Stark interference in the $6 {}^{1}S_{0} \to 6 {}^{3}P_{1}$ transition in ${}^{199}{Hg}$ , a process whereby a static electric field $E$ mixes magnetic dipole and electric quadrupole couplings into an electric dipole transition, leading to $E$ -linear energy shifts similar to those produced by a permanent atomic electric dipole moment (EDM). The measured interference amplitude, $a_{SI} = (a_{M 1} + a_{E 2}) = (5.8 \pm 1.5) \times 10^{- 9} (kV / cm)^{- 1}$ , agrees with relativistic, many-body predictions and confirms that earlier central-field estimates are a factor of 10 too large. More importantly, this study validates the capability of the ${}^{199}{Hg}$ EDM search apparatus to resolve nontrivial, controlled, and sub-nHz Larmor frequency shifts with EDM-like characteristics.

Received 23 November 2010

DOI:https://doi.org/10.1103/PhysRevLett.106.253002

Authors & Affiliations

T. H. Loftus^*, M. D. Swallows^†, W. C. Griffith^‡, M. V. Romalis^§, B. R. Heckel, and E. N. Fortson

Department of Physics, Box 351560, University of Washington, Seattle, Washington 98195-1560, USA

^*Present address: AOSense, Inc., Sunnyvale, CA 94085, USA.
^†Present address: JILA, University of Colorado, and NIST, Boulder, CO 80309, USA.
^‡Present address: Subatomic Physics Group, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
^§Permanent address: Department of Physics, Princeton University, Princeton, NJ 08544, USA.