Atomic-state diagnostics and optimization in cold-atom experiments

We report on the creation, observation and optimization of superposition states of cold atoms. In our experiments, rubidium atoms are prepared in a magneto-optical trap and later, after switching off the trapping fields, Faraday rotation of a weak probe beam is used to characterize atomic states prepared by application of appropriate light pulses and external magnetic fields. We discuss the signatures of polarization and alignment of atomic spin states and identify main factors responsible for deterioration of the atomic number and their coherence and present means for their optimization, like relaxation in the dark with the strobe probing. These results may be used for controlled preparation of cold atom samples and in situ magnetometry of static and transient fieldsComment: 15 pages and 9 figures (including supplementary information

Magneto-optical effects and rf magnetic field detection in cold rubidium atoms

We present the results of our latest experiments on atomic coherences in cold atoms. Interaction of atoms with a near-resonant, linearly polarized light leads to an effective creation of long-lived ground-state Zeeman coherences which is observed through the nonlinear Faraday effect or free induction decay signals of the Larmor precession. Both optically and radiofrequency induced Zeeman coherences are observed, with relaxation rates around a 100 Hz

Optical magnetometry based on nanodiamonds with nitrogen-vacancy color centers

Nitrogen-vacancy color centers in diamond are a very promising medium for many sensing applications such as magnetometry and thermometry. In this work, we study nanodiamonds deposited from a suspension onto glass substrates. Fluorescence and optically detected magnetic resonance spectra recorded with the dried-out nanodiamond ensembles are presented and a suitable scheme for tracking the magnetic-field value using a continuous poly-crystalline spectrum is introduced. Lastly, we demonstrate a remote-sensing capability of the high-numerical-aperture imaging fiber bundle with nanodiamonds deposited on its end facet

Integration of fluorescent, NV-rich nanodiamond particles with AFM cantilevers by focused ion beam for hybrid optical and micromechanical devices

In this paper, a novel fabrication technology of atomic force microscopy (AFM) probes integrating cantilever tips with an NV-rich diamond particle is presented. Nanomanipulation techniques combined with the focused electron beam-induced deposition (FEBID) procedure were applied to position the NV-rich diamond particle on an AFM cantilever tip. Ultrasonic treatment of nanodiamond suspension was applied to reduce the size of diamond particles for proper geometry and symmetry. The fabricated AFM probes were tested utilizing measurements of the electrical resistance at highly oriented pyrolytic graphite (HOPG) and compared with a standard AFM cantilever performance. The results showed novel perspectives arising from combining the functionalities of a scanning AFM with optically detected magnetic resonance (ODMR). In particular, it offers enhanced magnetometric sensitivity and the nanometric resolution

The influence of structure on selected properties of a lignocellulosic composite

The influence of structure on selected properties of a lignocellulosic composite. As part of the research, the influence of the number of layers and the structure of plywood on selected physico-mechanical properties was determined. The scope of work included: bending strength and modulus of elasticity, resistance at axial removal of screws and density profile. The influence of thickness increase on selected properties of plywood was confirmed. Flexural strength decreases by 60%, modulus of elasticity by 71%. As the number of composite layers increases, the screw holding capacity increases by 33%. Density oscillates around the value of 650 kg / m3, possible deviations occur through the influence of the anatomical structure of wood and glue joints.Wpływ struktury na wybrane właściwości kompozytu lignocelulozowego. Jako część badania wpływu liczby warstw i struktury sklejki na wybrane właściwości fizyko-mechaniczne określono właściwości. Zakres prac obejmował: wytrzymałość na zginanie i moduł sprężystości, nośność przy osiowe usuwanie śrub i profil gęstości. Wpływ przyrostu grubości na wybrane właściwości stali sklejka została potwierdzona. Wytrzymałość na zginanie spada o 60%, moduł sprężystości o 71%. Jako liczba zwiększa się liczba warstw kompozytu, zdolność trzymania śruby wzrasta o 33%. Gęstość oscyluje wokół wartości 650 kg/m3, możliwe odchylenia wynikają z wpływu budowy anatomicznej drewna i połączeń klejowych