Düsseldorf 2007 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 73: Laserspektroskopie II

Q 73.6: Talk

Friday, March 23, 2007, 15:15–15:30, 5K

Experimental investigations on the splitting of coherent population trapping resonances by the nuclear magnetic moment — •Roland Lammegger, Ivan Vasari, Christian Neureiter, and Laurentius Windholz — Inst. f. Experimentalphysik, Techn. Univ. Graz, Austria

Coherent population trapping (CPT) is a resonance phenomenon due to a quantum mechanical interference effect within an atomic system. The resonantly driven atomic level population is being trapped into a superpositional dark state, yielding the atomic medium transparent for the exciting electromagnetic fields. The observation of this effect requires a special electronic structure (Λ−system) and suitable lifetimes which can be found e.g. in alkali atoms.

We present experimental investigations on the behavior of the CPT resonances split by the nuclear magnetic moment under different external magnetic fields, laser polarizations and laser intensities. We focus our considerations on a special type of the Λ−System formation. In this case the center of gravity of the pair of split CPT resonances (called pseudoresonance) is sensitive to external magnetic fields only to second order in the magnetic field strenght.

The short term frequency stability of this pseudoresonance approaches the level of 10⁻¹⁴/√τ. Thus such resonances seems to be a good candidate for applications in compact atomic clocks used e.g. in GPS receivers and Satellites.