No abstract available

[en] The g-factor of the isomeric 9/2⁺ state in ⁸⁵Rb was measured using methods of time-differential and stroboscopic observation of the nuclear Larmor precession in the external magnetic field. The 9/2⁺ level (Tsub(1/2) = 1015 +- 1 ns, Esub(x) = 514 keV) was populated by the reaction ⁸⁵Rb (d,pn) sup(85m)Rb in natural rubidium at a deuteron energy of 11 MeV. From both measurements after correction for Knight shift and diamagnetic shielding an average value of g = + 1.369 +- 0.010 is obtained. (orig./LH)

[en] We demonstrate the first guiding of cold atoms through a 88 mm long piece of photonic band gap fiber. The guiding potential is created by a far-off resonance dipole trap propagating inside the fiber with a hollow core of 12 μm. We load the fiber from a dark spot ⁸⁵Rb magneto-optical trap and observe a peak flux of more than 10⁵ atoms s^-1 at a velocity of 1.5 m s^-1. With an additional reservoir optical dipole trap, a constant atomic flux of 1.5 x 10⁴ atoms s^-1 is sustained for more than 150 ms. These results open up interesting possibilities to study nonlinear light-matter interaction in a nearly one-dimensional geometry and pave the way for guided matter wave interferometry.

No abstract available

[en] We get a MOT in a conical hollow mirror which has a small hole of 150 μm at the apex. This is the pre-step to the generation of continuous cold atomic beam, atom lithography and atom deposition experiments.

[en] In this manuscript, we observed narrowing of electromagnetically induced transparency (EIT) spectral width by using superimposed Laguerre–Gaussian (LG) beams for coupling light. EIT with narrow transparency width has a potential application towards slow light for quantum memory devices. LG beams of σ ⁺ and σ ⁻ polarization are superimposed and used as coupling light for an EIT experiment. A theoretical model is discussed using a semi-classical treatment and the experimental part confirms the narrowing of EIT width for higher values of ‘l’. (paper)

[en] Full text: In recent years there has been significant interest in studies on the development of neutral atom traps and the applications thereof. One novel approach to the development of miniature atom traps involves the optical near-fields formed by laser diffraction on an array of circular apertures in a thin screen. This approach can be adapted in order to fabricate an array of atom microtraps and, accordingly, produce a large number of trapped atomic microensembles from a single initial atomic cloud or beam. In this paper, we propose and analyze such near-field Fresnel-type atom microtraps with a characteristic aperture size approximately equal to the optical wavelength incident on the thin screen. Our analysis of the atom microtraps shows that, for a moderate laser intensity of about 10 W/cm², the traps can store atoms with a kinetic energy equivalent to ∼ 100 μK, and with estimated lifetimes of ∼ 1 second. Our analysis for ⁸⁵Rb and ¹³³Cs atoms shows that the potential well depth of the micro-traps is mainly determined by the intensity of the incident laser field and the detuning. By varying these two parameters one can achieve robust control over the trap parameters. The incident laser intensity of 10 W/cm² corresponds to about 0.5 μW of laser power incident on each individual aperture. With such trap parameters one can perform atom optics experiments by blending microfabrication technology with cold atoms for site selective addressing of microtraps. (author)

[en] We report an experimental investigation of electromagnetically induced transparency in a multi-level cascade system of cold ⁸⁵Rb atoms. The absorption spectral profiles of the probe light and their dependence on the intensity of the coupling laser were investigated. The experimental measurements agree with the theoretical calculations

[en] Coherent backscattering of light by optically dense atomic ensembles is considered. The spectrum of scattered radiation is studied. The dynamics of the total intensity and enhancement factor is considered in the case of scattering of pulsed radiation. The spectral and temporal characteristics of coherent backscattering are analysed depending on the observation conditions. As an example, calculations are performed for an ensemble of ⁸⁵Rb atoms in a magnetooptical trap. It is shown that analysis of the correlation and dynamic properties of scattered radiation makes it possible to separate contributions from different orders of scattering and thereby to study the process of radiation trapping in dense media in more detail. (fourth seminar to the memory of d.n. klyshko)

[en] We show that portions of an image written into a gradient echo memory can be individually retrieved or erased on demand, an important step toward processing a spatially multiplexed quantum signal. Targeted retrieval is achieved by locally addressing the transverse plane of the storage medium, a warm ⁸⁵Rb vapor, with a far-detuned control beam. Spatially addressable erasure is similarly implemented by imaging a bright beam tuned near the ⁸⁵Rb D₁ line in order to scatter photons and induce decoherence. Under our experimental conditions atomic diffusion is shown to impose an upper bound on the effective spatial capacity of the memory. The decoherence induced by the optical eraser is characterized and modeled as the response of a two-level atom in the presence of a strong driving field. (paper)