Excitation of atomic and nuclear coherence by strong optical fields

Yuri V. Rostovtsev

Yuri V. Rostovtsev

We study population transfer and excitation of quantum coherence in atomic and nuclear systems interacting with strong ultra-short laser pulses. We discuss CEP effects and possible applications to cooperative generation of XUV and nuclear radiation.

Martin M. Boyd, Tanya Zelevinsky, Andrew D. Ludlow +4 more

Highest-resolution laser spectroscopy has generally been limited to single trapped ion systems because of the rapid decoherence that plagues neutral atom ensembles. Precision spectroscopy of ultracold neutral atoms confined in a trapping potential now shows superior optical coherence without any deleterious effects from motional degrees of freedom, revealing optical resonance linewidths at the hertz level with a good signal-to-noise ratio. The resonance quality factor of 2.4 x 10(14) is the highest ever recovered in any form of coherent spectroscopy. The spectral resolution permits direct observation of the breaking of nuclear spin degeneracy for the 1S0 and 3P0 optical clock states of 87Sr under a small magnetic bias field. This optical approach for excitation of nuclear spin states allows an accurate measurement of the differential Landé g factor between 1S0 and 3P0. The optical atomic coherence demonstrated for collective excitation of a large number of atoms will have a strong impact on quantum measurement and precision frequency metrology.

I. N. Izosimov

Ulrich Krohn, Vera Bendkowsky, Rolf Heidemann +3 more

When ground state atoms are excited to a Rydberg state, van der Waals interactions among them can lead to a strong suppression of the excitation. Despite the strong interactions the evolution can still be reversed by a simple phase shift in the excitation laser field. We experimentally prove the coherence of the excitation in the strong blockade regime by applying an "optical rotary echo" technique to a sample of magnetically trapped ultracold atoms, analogous to a method known from nuclear magnetic resonance. We additionally measured the dephasing time due to the interaction between the Rydberg atoms.

Павел Абрамович Головинский, M. E. Alferieff