Abstract
We study the index of refraction of an ultracold bosonic gas in the dilute regime. Using phase-contrast imaging with light detuned from resonance by several tens of linewidths, we image a single cloud of ultracold atoms for 100 consecutive shots, which enables the study of the scattering rate as a function of temperature and density using only a single cloud. We observe that the scattering rate is increased below the critical temperature for Bose-Einstein condensation by a factor of 3 compared to the single-atom scattering rate. We show that current atom-light interaction models to second order of the density show a similar increase, where the magnitude of the effect depends on the model that is used to calculate the pair-correlation function. This confirms that the effect of quantum statistics on the index of refraction is dominant in this regime.
- Received 22 October 2015
DOI:https://doi.org/10.1103/PhysRevLett.116.173602
© 2016 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
Losing Light in a BEC
Published 28 April 2016
The index of refraction in a gas of bosons is enhanced relative to its value in a classical gas, a predicted quantum effect that has now been observed in ultracold sodium atoms.
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