Optically trapped atom interferometry using the clock transition of large Rb-87 Bose-Einstein condensates - Quantum PhysicsReportar como inadecuado




Optically trapped atom interferometry using the clock transition of large Rb-87 Bose-Einstein condensates - Quantum Physics - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We present a Ramsey-type atom interferometer operating with an opticallytrapped sample of 10^6 Bose-condensed Rb-87 atoms. The optical trap allows usto couple the |F =1, mF =0> ightarrow |F =2, mF =0> clock states using asingle photon 6.8GHz microwave transition, while state selective readout isachieved with absorption imaging. Interference fringes with contrastapproaching 100% are observed for short evolution times. We analyse the processof absorption imaging and show that it is possible to observe atom numbervariance directly, with a signal-to-noise ratio ten times better than theatomic projection noise limit on 10^6 condensate atoms. We discuss thetechnical and fundamental noise sources that limit our current system, andoutline the improvements that can be made. Our results indicate that, withfurther experimental refinements, it will be possible to produce and measurethe output of a sub-shot-noise limited, large atom number BEC-basedinterferometer.In an addendum to the original paper, we attribute our inability to observequantum projection noise to the stability of our microwave oscillator andbackground magnetic field. Numerical simulations of the Gross-Pitaevskiiequations for our system show that dephasing due to spatial dynamics driven byinterparticle interactions account for much of the observed decay in fringevisibility at long interrogation times. The simulations show good agreementwith the experimental data when additional technical decoherence is accountedfor, and suggest that the clock states are indeed immiscible. With smallersamples of 5 \times 10^4 atoms, we observe a coherence time of {\tau} =1.0+0.5-0.3 s.



Autor: P.A. Altin, G. McDonald, D. Döring, J.E. Debs, T. Barter, N.P. Robins, J.D. Close, S.A. Haine, T.M. Hanna, R.P. Anderson

Fuente: https://arxiv.org/







Documentos relacionados