Ultrafast optical spectroscopy of spectral fluctuations in a dense atomic vapor.
Transient four-wave mixing experiments with 100 fs pulses in a dense potassium vapor probe the electronic energy fluctuations that lead to optical decoherence. Echo-peak shift experiments yield a biexponential two-time correlation function of energy level fluctuations. Molecular dynamics simulations show that the slow component is a many-body excitonic contribution arising from long-range resonant interactions. The decay of the correlation function occurs on comparable time scales in theory and experiment.
Lorenz
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JILA, University of Colorado, Boulder, CO 80309-0440, USA.
Mukamel
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Zhuang
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Cundiff
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