Zeeman frequency shifts in an optical dipole trap used to search for an electric-dipole moment
| Autor: | E. N. Fortson, Michael Romalis |
|---|---|
| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Physical Review A. 59:4547-4558 |
| ISSN: | 1094-1622 1050-2947 |
| DOI: | 10.1103/physreva.59.4547 |
| Popis: | We calculate the Zeeman frequency shifts due to interactions with the light in a far-off-resonance optical dipole trap. These shifts are important for potential use of such a trap to search for an atomic permanent electric-dipole moment ~EDM!. We present numerical results for Cs and Hg, as examples of paramagnetic and diamagnetic atoms. The vector and tensor light shifts are calculated for a large range of trap optical frequencies, for both red-detuned and blue-detuned traps. We also consider frequency shifts resulting from magnetic dipole and electric quadrupole transitions mixed in by a static electric field. These shifts are particularly important for EDM experiments since they are linear in the electric field. The Zeeman frequency shifts represent a substantial problem for EDM experiments in a dipole trap and must be controlled with care to achieve theoretical sensitivity. @S1050-2947~99!02806-1# PACS number~s!: 32.80.Pj, 32.60.1i, 32.10.Dk, 11.30.Er I. INTRODUCTION The search for a permanent electric-dipole moment ~EDM! is an effective method of probing for physics beyond the standard model @1#. A nonzero value of the EDM requires violation of T and P invariance. If the CPT symmetry is not violated, it also implies CP violation. Within the standard model the EDMs are unmeasurably small, but many extensions of the standard model predict EDMs well within experimental reach. Techniques of laser cooling and trapping of neutral atoms open new possibilities for EDM experiments @2,3#. In one of the more promising methods, cold atoms are held between high-voltage electrodes in an optical dipole trap, and the coupling between the static electric field and the atomic EDM produces a shift of the Zeeman levels of the atoms. However, the Zeeman levels would also be shifted by the interactions with the trapping laser fields. In this paper we present a systematic analysis of the various Zeeman energy shifts due to the laser fields in an optical dipole trap, and discuss how they might limit the sensitivity of an EDM experiment. We find that such shifts will impose tight constraints on the design of the experiment. An atom with a permanent electric-dipole moment d and a magnetic dipole moment m interacts with electric and magnetic fields E and B according to the following Hamiltonian |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|