Взаимодействие одиночных атомов с сильно сфокусированным световым полем - PDF

Взаимодействие одиночных атомов с сильно сфокусированным световым полем Syed Abdullah Aljunid, Jianwei Lee, Brenda Chng, Martin Paesold, Dao Hoang Lan, Teo Zhi Wei Colin*, Kadir Durak, Gleb Maslennikov,

Please download to get full document.

View again

of 20
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.


Publish on:

Views: 2 | Pages: 20

Extension: PDF | Download: 0

Взаимодействие одиночных атомов с сильно сфокусированным световым полем Syed Abdullah Aljunid, Jianwei Lee, Brenda Chng, Martin Paesold, Dao Hoang Lan, Teo Zhi Wei Colin*, Kadir Durak, Gleb Maslennikov, Valerio Scarani*, Christian Kurtsiefer Former members: Meng Khoon Tey, Zilong Chen, Timothy Liew*, Florian Huber Motivation Quantum Information and Communication protocols information exchange between flying qubits (photons) and stationary qubits (atoms) absorption triggered phase shift EFFICIENCY OF ATOM-PHOTON INTERFACE Basic Problem Get strong coupling between an atom and a light field on the single photon level electromagnetic field / photon -level atom Use a cavity ( ) High electrical field strength even for a single photon Preferred spontaneous emission into the cavity mode A cavity can enhance the interaction between a propagating external mode and an atom Many ongoing experiments CalTech, Univ. of Georgia, MPQ, etc Lens-based Or just use a (good) lens to focus light to an atom Take a Gaussian beam (laser, single-mode fiber) and do estimation E L paraxial approximation w L w f E A R P = P in 3λ πw = f 3λ πw σ L max E E A L /A Oversimplified model --- doesn t apply for strong focusing Modelling Let the field have a spherical wave front after the lens and write it in vectorial form compatible with Maxwell equations Gaussian mode Propagate field to the focus mode decomposition f parabolic wavefront: S. van Enk et al., 001, (Phys.Rev.A 63, 03809) spherical wavefront: M.K. Tey et al., 009. (NJP, 11, ) use Green theorem for a closed expression for field at focus E A determine atom response from semiclassical excitation probability for a given field 3 for weak, on-resonant excitation 0EA P 4 obtain the attering ratio R P P in Modelling results Scattering ratio for Gaussian beam 3 1, 4 1 1, : u u u e u P P R u in f w u L focusing strength 1!!! R Energy conserved!?!? w L f Interference The total field is a superposition of the excitation and attered field E Tot r E r E r in E Zumofen, et al. Phys.Rev.Lett.101, E r E A 3 e i kr kr ˆ ˆ dipolar phase lag rˆ rˆ transition E L E L The outgoing power is defined up to a constant P out E Tot P in P dr * * E r E r E r E r in assures no energy conservation violation in Projection into fiber Since no detector covers the full solid angle, we only partially collect the outgoing power natural choice --- projection onto the same mode as excitation P out g, ETot, g E E x gx k nda Integration can be carried out and we obtain experimentally measured quantities L T xs Tot g Transmission T Pout R 1 1 P Reflectivity in R R 4 R S arg1 Losses L R Near-resonant phase shift R R i i Experiment AC Stark shift Circularly polarized dipole trap defines the quantization axis and splits the degeneracy of hyperfine states F = 3 F = trapping potential The real thing.5 cm Results u = 0.9 u = 0.9 Experiment T min = 89.7 ± 0.7 % R max = 0.17 ± 0.05 % δφ max = 0.98 ± 0.07 ⁰ Theory T min = 79.6 % R max = 0.9 % δφ max =.3 ⁰ u = 0.4 Theory vs Experiment u=.4 Experiment Two reasons for direpancy: atomic motion around the focal point aberrations of the lens Temperature! MUST cool down the atom if high extinction values needed! Sideband cooling Beam geometry: Trap frequencies: 55 khz, 7 khz l Sideband cooling average motional state after cooling sequence n B-field sensitivity: ~ khz/mg 0 mg enough to shift the peak active stabilization to mg level required. Заключение Атом в сильно сфокусированном световом пучке, способен «сильно» рассеивать поле. Построена теоретическая модель, описывающая взаимодействие атома с сильно сфокусированными пучками света. За счет рамановского охлаждения, атом может быть охлажден до «почти» основного состояния ловушки Спасибо! Syed Abdullah Aljunid Meng Khoon Tey (now UIBK) Zilong Chen (now JILA) ( Harvard Florian Huber (now Brenda Chng Jianwei Lee Martin Paesold Dao Hoang Lan Teo Zhi Wei Colin ( UK Timothy Liew (now Gleb Maslennikov Valerio Scarani Christian Kurtsiefer Single atom (almost) Hanbury-Brown Twiss experiment on atomic fluoreence during cooling D 1 D photon antibunching Rabi oillation
Related Search
Similar documents
View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks