Collisional decoherence of internal state superpositions in a trapped ultracold gas
| Autor: | Hemming, C. J., Krems, R. V. |
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| Rok vydání: | 2009 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevA.81.052701 |
| Popis: | 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. Comment: 32 pages, 2 figures. Changes for v.2: background discussion expanded; references to and discussion of related work added to and expanded; calculation of an additional quantity characterizing coherence added (Fig. 2 added in relation to this); Eq. (19) of v.1 was not correct |
| Databáze: | arXiv |
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