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arXiv · 0908.3204

Collisional decoherence of internal state superpositions in a trapped ultracold gas

C. J. Hemming·R. V. Krems
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Abstract

We analyze collisional decoherence of atoms or molecules prepared in a coherent superposition of nondegenerate internal states at ultralow temperatures and placed in an ultracold buffer gas. Our analysis is applicable for an arbitrary bath particle/tracer particle mass ratio. Both elastic and inelastic collisions contribute to decoherence. We obtain an expression relating the observable decoherence rate to pairwise scattering properties, specifically the low-temperature scattering amplitudes. We consider the dependence on the bath particle/tracer particle mass ratio for the case of light bath and heavy tracer particles. The expressions obtained may be useful in low-temperature applications where accurate estimates of decoherence rates are needed. The results suggest a method for determining the scattering lengths of atoms and molecules in different internal states by measuring decoherence-induced damping of coherent oscillations.

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C. J. Hemming, R. V. Krems. 2010-02-04. Collisional decoherence of internal state superpositions in a trapped ultracold gas. https://doi.org/10.1103/physreva.81.052701

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