Journal articles: 'Cold atom traps'

1

Härter, A., and J. Hecker Denschlag. "Cold atom–ion experiments in hybrid traps." Contemporary Physics 55, no. 1 (January 2, 2014): 33–45. http://dx.doi.org/10.1080/00107514.2013.854618.

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2

Cherry, O., J. D. Carter, and J. D. D. Martin. "An atom chip for the manipulation of ultracold atoms." Canadian Journal of Physics 87, no. 6 (June 2009): 633–38. http://dx.doi.org/10.1139/p09-043.

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We have fabricated an atom chip that magnetically traps laser cooled 87Rb by generating high magnetic-field gradients using micrometre scale current-carrying wires. The wires are fabricated on a Si wafer (with a 40 nm SiO2 layer) using 1.2 μm thick Au and a 20 nm thick adhesion layer, and are patterned with lift-off photolithography. We characterize the number and temperature of the cold atoms trapped by the chip.

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3

Dimova, E., O. Morizot, G. Stern, C. L. Garrido Alzar, A. Fioretti, V. Lorent, D. Comparat, H. Perrin, and P. Pillet. "Continuous transfer and laser guiding between two cold atom traps." European Physical Journal D 42, no. 2 (February 2, 2007): 299–308. http://dx.doi.org/10.1140/epjd/e2007-00022-0.

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4

DE OLIVEIRA, M. C., and B. R. DA CUNHA. "COLLISION-DEPENDENT ATOM TUNNELING RATE — BOSE–EINSTEIN CONDENSATES IN DOUBLE AND MULTIPLE WELL TRAPS." International Journal of Modern Physics B 23, no. 32 (December 30, 2009): 5867–80. http://dx.doi.org/10.1142/s0217979209054818.

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The overlap of localized wave functions in a two-mode approximation leads to interaction (cross-collision) between ultra-cold atoms trapped in distinct sites of a double-well potential. We show that this interaction can significantly change the atom tunneling rate for special trap configurations resulting in an effective linear Rabi regime of population oscillation between the trap wells. In this sense, we demonstrate that cross-collisional effects can significantly extend the validity of the two-mode model approach allowing it to be alternatively employed to explain the recently observed increase of tunneling rates due to nonlinear interactions. Moreover, we investigate the extension for ultra-cold atoms trapped in an optical lattice. Control over the cross-collisional terms, obtained through manipulation of the optical trapping potential, can be used as an engineering tool to study many-body physics.

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Jian-Ping, Yin, Gao Wei-Jian, and Hu Jian-Jun. "Arrays of microscopic magnetic traps for cold atoms and their applications in atom optics." Chinese Physics 11, no. 5 (April 26, 2002): 472–80. http://dx.doi.org/10.1088/1009-1963/11/5/312.

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6

Timmermans, Eddy. "Progress and Prospects of Fermi Gas Physics in Cold Atom Traps." Physica Scripta 110 (2004): 302. http://dx.doi.org/10.1238/physica.topical.110a00302.

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7

Al-Amri, M., and M. Babiker. "Atomic reflection off conductor walls as a tool in cold atom traps." European Physical Journal D 48, no. 3 (June 13, 2008): 417–21. http://dx.doi.org/10.1140/epjd/e2008-00116-1.

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8

Yurovsky, V. A., and A. Ben-Reuven. "Incomplete optical shielding in cold atom traps: three-dimensional Landau-Zener theory." Physical Review A 55, no. 5 (May 1, 1997): 3772–79. http://dx.doi.org/10.1103/physreva.55.3772.

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9

Zhou, Feng, Xiao Li, Min Ke, Jin Wang, and Ming-Sheng Zhan. "Microwave coherent manipulation of cold atoms in optically induced fictitious magnetic traps on an atom chip." Chinese Physics B 26, no. 9 (August 2017): 090701. http://dx.doi.org/10.1088/1674-1056/26/9/090701.

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10

Niranjan, M., Anand Prakash, and S. A. Rangwala. "Analysis of Multipolar Linear Paul Traps for Ion–Atom Ultracold Collision Experiments." Atoms 9, no. 3 (June 29, 2021): 38. http://dx.doi.org/10.3390/atoms9030038.

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We evaluate the performance of multipole, linear Paul traps for the purpose of studying cold ion–atom collisions. A combination of numerical simulations and analysis based on the virial theorem is used to draw conclusions on the differences that result, by considering the trapping details of several multipole trap types. Starting with an analysis of how a low energy collision takes place between a fully compensated, ultracold trapped ion and an stationary atom, we show that a higher order multipole trap is, in principle, advantageous in terms of collisional heating. The virial analysis of multipole traps then follows, along with the computation of trapped ion trajectories in the quadrupole, hexapole, octopole and do-decapole radio frequency traps. A detailed analysis of the motion of trapped ions as a function of the amplitude, phase and stability of the ion’s motion is used to evaluate the experimental prospects for such traps. The present analysis has the virtue of providing definitive answers for the merits of the various configurations, using first principles.

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11

Band, Y. B., and P. S. Julienne. "Optical-Bloch-equation method for cold-atom collisions: Cs loss from optical traps." Physical Review A 46, no. 1 (July 1, 1992): 330–43. http://dx.doi.org/10.1103/physreva.46.330.

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12

Melezhik, Vladimir S. "Efficient computational scheme for ion dynamics in RF-field of Paul trap." Discrete and Continuous Models and Applied Computational Science 27, no. 4 (December 15, 2019): 378–85. http://dx.doi.org/10.22363/2658-4670-2019-27-4-378-385.

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We have developed an efficient computational scheme for integration of the classical Hamilton equations describing the ion dynamics confined in the radio-frequency field of the Paul trap. It has permitted a quantitative treatment of cold atom-ion resonant collisions in hybrid atom-ion traps with taking into account unremovable ion micromotion caused by the radio-frequency fields (V.S. Melezhik et. al., Phys. Rev. A100, 063406 (2019)). The important element of the hybrid atom-ion systems is the electromagnetic Paul trap confining the charged ion. The oscillating motion of the confined ion is defined by two frequencies of the Paul trap. It is the frequency of the order of 100 kHz due to the constant electric field and the radio-frequency of about 1-2 MHz defined by the alternating electromagnetic field of the ion trap. The necessity to accurately treat the ion motion in the combined field with two time scales defined by these two very different frequencies has demanded to develop the stable computational scheme for integration of the classical Hamilton equations for the ion motion. Moreover, the scheme must be stable on rather long time-interval of the ion collision with the cold atom ∼ 10 × 2/ defined by the atomic trap frequency ∼ 10 kHz and in the moment of the atom-ion collision when the Hamilton equations are strongly coupled. The developed numerical method takes into account all these features of the problem and makes it possible to integrate the system of coupled quantum-semiclassical equations with the necessary accuracy and quantitatively describes the processes of atomic-ion collisions in hybrid traps, including resonance effects.

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13

van Wijngaarden, W. A., and J. Clarke. "Article." Canadian Journal of Physics 76, no. 4 (April 1, 1998): 305–10. http://dx.doi.org/10.1139/p98-015.

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A neutral atom trap is proposed consisting of a magnetic field generated by a pair of anti-Helmholtz coils and a fringing electric field of a parallel plate capacitor. The electric field shifts the energy minimum ofthe trap away from the point where the magnetic field is zero thus preventingatom loss from the trap due to Majorana transitions. This trap offers someadvantages over existing traps that are used to study cold atoms.PACS Nos.: 32.80Pj and 03.75Fi

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14

Fruchtman, Amir, and Baruch Horovitz. "Single vortex fluctuations in a superconducting chip as generating dephasing and spin flips in cold atom traps." EPL (Europhysics Letters) 99, no. 5 (September 1, 2012): 53002. http://dx.doi.org/10.1209/0295-5075/99/53002.

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15

Béguin, J. B., J. Laurat, X. Luan, A. P. Burgers, Z. Qin, and H. J. Kimble. "Reduced volume and reflection for bright optical tweezers with radial Laguerre–Gauss beams." Proceedings of the National Academy of Sciences 117, no. 42 (October 2, 2020): 26109–17. http://dx.doi.org/10.1073/pnas.2014017117.

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Spatially structured light has opened a wide range of opportunities for enhanced imaging as well as optical manipulation and particle confinement. Here, we show that phase-coherent illumination with superpositions of radial Laguerre–Gauss (LG) beams provides improved localization for bright optical tweezer traps, with narrowed radial and axial intensity distributions. Further, the Gouy phase shifts for sums of tightly focused radial LG fields can be exploited for phase-contrast strategies at the wavelength scale. One example developed here is the suppression of interference fringes from reflection near nanodielectric surfaces, with the promise of improved cold-atom delivery and manipulation.

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16

Jessen, P. S., D. L. Haycock, G. Klose, G. A. Smith, I. H. Deutsch, and G. K. Brennen. "Quantum control and information processing in optical lattices." Quantum Information and Computation 1, Special (December 2001): 20–32. http://dx.doi.org/10.26421/qic1.s-5.

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Neutral atoms offer a promising platform for single- and many-body quantum control, as required for quantum information processing. This includes excellent isolation from the decohering influence of the environment, and the existence of well developed techniques for atom trapping and coherent manipulation. We present a review of our work to implement quantum control and measurement for ultra-cold atoms in far-off-resonance optical lattice traps. In recent experiments we have demonstrated coherent behavior of mesoscopic atomic spinor wavepackets in optical double-well potentials, and carried out quantum state tomography to reconstruct the full density matrix for the atomic spin degrees of freedom. This model system shares a number of important features with proposals to implement quantum logic and quantum computing in optical lattices. We present a theoretical analysis of a protocol for universal quantum logic via single qubit operations and an entangling gate based on electric dipole-dipole interactions. Detailed calculations including the full atomic hyperfine structure suggests that high-fidelity quantum gates are possible under realistic experimental conditions.

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17

Doser, M., S. Aghion, C. Amsler, G. Bonomi, R. S. Brusa, M. Caccia, R. Caravita, et al. "AEgIS at ELENA: outlook for physics with a pulsed cold antihydrogen beam." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 376, no. 2116 (February 19, 2018): 20170274. http://dx.doi.org/10.1098/rsta.2017.0274.

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The efficient production of cold antihydrogen atoms in particle traps at CERN’s Antiproton Decelerator has opened up the possibility of performing direct measurements of the Earth’s gravitational acceleration on purely antimatter bodies. The goal of the AEgIS collaboration is to measure the value of g for antimatter using a pulsed source of cold antihydrogen and a Moiré deflectometer/Talbot–Lau interferometer. The same antihydrogen beam is also very well suited to measuring precisely the ground-state hyperfine splitting of the anti-atom. The antihydrogen formation mechanism chosen by AEgIS is resonant charge exchange between cold antiprotons and Rydberg positronium. A series of technical developments regarding positrons and positronium (Ps formation in a dedicated room-temperature target, spectroscopy of the n =1–3 and n =3–15 transitions in Ps, Ps formation in a target at 10 K inside the 1 T magnetic field of the experiment) as well as antiprotons (high-efficiency trapping of , radial compression to sub-millimetre radii of mixed plasmas in 1 T field, high-efficiency transfer of to the antihydrogen production trap using an in-flight launch and recapture procedure) were successfully implemented. Two further critical steps that are germane mainly to charge exchange formation of antihydrogen—cooling of antiprotons and formation of a beam of antihydrogen—are being addressed in parallel. The coming of ELENA will allow, in the very near future, the number of trappable antiprotons to be increased by more than a factor of 50. For the antihydrogen production scheme chosen by AEgIS, this will be reflected in a corresponding increase of produced antihydrogen atoms, leading to a significant reduction of measurement times and providing a path towards high-precision measurements. This article is part of the Theo Murphy meeting issue ‘Antiproton physics in the ELENA era’.

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18

Milborrow, B. V., and H.-S. Lee. "Endogenous Biosynthetic Precursors of (+)-Abscisic Acid. IV. Biosynthesis of ABA from [2Hn] Carotenoids by a Cell-free System from Avocado." Functional Plant Biology 24, no. 6 (1997): 715. http://dx.doi.org/10.1071/pp96100.

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The supernatant fraction (12 000 g) of a homogenate of avocado mesocarp incorporated 3-R-[2-14C]mevalonate (54 µCi/µmol, 0.9 µCi/5mL) into ABA and was used to examine the incorporation of carotenoids into ABA. [2Hn]carotenoids were isolated by HPLC from mustard (Sinapis alba) seedlings that had germinated in closed flasks in 2H2O (55 atom%). The carotenoids were dissolved in Tween 80 and acetone (1:1 v/v; 100 µL) and added to the cell-free system final vol. 5 mL, pH 7.1, together with cofactors. After 16 h incubation in darkness the ABA was isolated by HPLC and converted into the pentafluorobenzyl ester. The samples were analysed by capillary gas–liquid chromatography and the CH4 chemical ionisation, negative ion mass spectra recorded. Deuterium-labelled ABA was detected when [2H] carotenoids were supplied. ‘Cold traps’ of unlabelled carotenoids added to the cell-free system lowered the [14C]mevalonate incorporated into ABA to 33% of the control value (1195 dpm) (trans-viola, 33%; trans-neo, 32%) but with 9´ -cis-neoxanthin the value fell to 29%. The addition of naproxen (an inhibitor of lipoxygenases) hardly increased the 14C trapped in trans-viola- or trans-neoxanthin but reduced the 14C in ABA to 17% of the control and raised the 14C trapped by the 9´-cis-neoxanthin by 179%. These changes support earlier suggestions that it is 9´-cis-neoxanthin that is cleaved to give the future ABA residue. Other metabolic inhibitors (bisulfite, AMO 1618, tungstate, CO, piperonyl butoxide) affected the incorporation of [14C]mevalonate into ABA by the cell-free system and the incorporation of [14C]mevalonolactone into ABA formed in slices of avocado fruit in a closely similar way. This provides strong support for ABA’s being biosynthesised in the cell-free system by the same reactions as those by which it is made in vivo.

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19

Sinclair, C. D. J., J. A. Retter, E. A. Curtis, B. V. Hall, I. Llorente Garcia, S. Eriksson, B. E. Sauer, and E. A. Hinds. "Cold atoms in videotape micro-traps." European Physical Journal D 35, no. 1 (June 14, 2005): 105–10. http://dx.doi.org/10.1140/epjd/e2005-00088-6.

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20

Diry, Fabienne, Michael Mestre, Bruno Viaris de Lesegno, and Laurence Pruvost. "Cold atoms in holographically shaped optical traps." Journal of Physics: Conference Series 194, no. 12 (November 1, 2009): 122010. http://dx.doi.org/10.1088/1742-6596/194/12/122010.

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21

LYUKSYUTOV, I. F. "NANOSCALE MAGNETIC TRAPS." Modern Physics Letters B 16, no. 15n16 (July 10, 2002): 569–76. http://dx.doi.org/10.1142/s0217984902004081.

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We show that nanofabricated magnetic textures allow the trapping and manipulation of nanosize diamagnetic systems, such as carbon nanotubes, proteins and membranes as well as cold atoms. The latter can have temperatures as high as 1 K. Magnetic textures which can be used as traps, include films, dots and nanowires, both single and in arrays. Manipulation with trapped nanoparticles/atoms is possible by using external magnetic fields. We also briefly discuss prospects for magnetic traps at the micron scale.

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22

Oh, Eun, and Shengwang Du. "Manipulating cold atoms with off-axis rotating traps." Journal of the Korean Physical Society 63, no. 4 (August 2013): 938–42. http://dx.doi.org/10.3938/jkps.63.938.

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23

Friedman, Nir, Lev Khaykovich, Roee Ozeri, and Nir Davidson. "Single-Beam Dark Optical Traps for Cold Atoms." Optics and Photonics News 10, no. 12 (December 1, 1999): 36. http://dx.doi.org/10.1364/opn.10.12.000036.

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24

Lev, B. "Fabrication of micro-magnetic traps for cold neutral atoms." Quantum Information and Computation 3, no. 5 (2003): 450–64. http://dx.doi.org/10.26421/qic3.5-5.

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Many proposals for quantum information processing require precise control over the motion of neutral atoms, as in the manipulation of coherent matter waves or the confinement and localization of individual atoms. Patterns of micron-sized wires, fabricated lithographically on a flat substrate, can conveniently produce large magnetic-field gradients and curvatures to trap cold atoms and to facilitate the production of Bose-Einstein condensates. The intent of this paper is to provide the researcher who has access to a standard clean-room enough information to design and fabricate such devices.

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25

Zaretskii, D. F., and S. B. Sazonov. "Thermalization of neutrons on cold atoms in magnetic traps." Journal of Experimental and Theoretical Physics Letters 70, no. 9 (November 1999): 575–77. http://dx.doi.org/10.1134/1.568217.

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26

Buchachenko, A. A., Yu V. Suleimanov, M. M. Szczęśniak, and G. Chałasiński. "Interactions and collisions of cold metal atoms in magnetic traps." Physica Scripta 80, no. 4 (October 2009): 048109. http://dx.doi.org/10.1088/0031-8949/80/04/048109.

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27

CAZALILLA, M. A., A. F. HO, and T. GIAMARCHI. "DECONFINEMENT AND COLD ATOMS IN OPTICAL LATTICES." International Journal of Modern Physics B 20, no. 30n31 (December 20, 2006): 5169–78. http://dx.doi.org/10.1142/s0217979206036235.

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Despite the fact that by now one dimensional and three dimensional systems of interacting particles are reasonably well understood, very little is known on how to go from the one dimensional physics to the three dimensional one. This is in particular true in a quasi-one dimensional geometry where the hopping of particles between one dimensional chains or tubes can lead to a dimensional crossover between a Luttinger liquid and more conventional high dimensional states. Such a situation is relevant to many physical systems. Recently cold atoms in optical traps have provided a unique and controllable system in which to investigate this physics. We thus analyze a system made of coupled one dimensional tubes of interacting fermions. We explore the observable consequences, such as the phase diagram for isolated tubes, and the possibility to realize unusual superfluid phases in coupled tubes systems.

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28

Bober, M., J. Zachorowski, W. Gawlik, P. Morzyński, M. Zawada, D. Lisak, A. Cygan, et al. "Precision spectroscopy of cold strontium atoms, towards optical atomic clock." Bulletin of the Polish Academy of Sciences: Technical Sciences 60, no. 4 (December 1, 2012): 707–10. http://dx.doi.org/10.2478/v10175-012-0082-x.

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Abstract This report concerns the experiment of precision spectroscopy of cold strontium atoms in the Polish National Laboratory of Atomic, Molecular and Optical Physics in Toruń. The system is composed of a Zeeman slower and magneto-optical traps (at 461 nm and 689 nm), a frequency comb, and a narrow-band laser locked to an ultra-stable optical cavity. All parts of the experiment are prepared and the first measurements of the absolute frequency of the 1S0-3P1, 689 nm optical transition in 88Sr atoms are performed.

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29

Han, Jing-Shan, Xin-Ping Xu, Hai-Chao Zhang, and Yu-Zhu Wang. "Optimal transport of cold atoms by modulating the velocity of traps." Chinese Physics B 22, no. 2 (February 2013): 023702. http://dx.doi.org/10.1088/1674-1056/22/2/023702.

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30

Grabowski, A., and T. Pfau. "A lattice of magneto-optical and magnetic traps for cold atoms." European Physical Journal D 22, no. 3 (March 2003): 347–54. http://dx.doi.org/10.1140/epjd/e2003-00047-3.

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31

Ji Xian-Ming, Lu Jun-Fa, Mu Ren-Wang, and Yin Jian-Ping. "Array of micro-optical traps for cold atoms or cold molecules using a Damman grating." Acta Physica Sinica 55, no. 7 (2006): 3396. http://dx.doi.org/10.7498/aps.55.3396.

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32

Krzyzanowska, K., M. Copley-May, R. Romain, C. MacCormick, and S. Bergamini. "Quantum-enhanced protocols with mixed states using cold atoms in dipole traps." Journal of Physics: Conference Series 793 (January 2017): 012015. http://dx.doi.org/10.1088/1742-6596/793/1/012015.

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33

Bagnato, V. S., N. P. Bigelow, L. G. Marcassa, and S. C. Zilio. "Observation of Double Stable Clouds of Cold Atoms in Magneto-Optical Traps." Japanese Journal of Applied Physics 35, Part 1, No. 9A (September 15, 1996): 4664–67. http://dx.doi.org/10.1143/jjap.35.4664.

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34

Stotland, A., D. Cohen, and N. Davidson. "Semilinear response for the heating rate of cold atoms in vibrating traps." EPL (Europhysics Letters) 86, no. 1 (April 2009): 10004. http://dx.doi.org/10.1209/0295-5075/86/10004.

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35

Milborrow, B. V., and H. S. Lee. "Endogenous biosynthetic precursors of (+)-abscisic acid. VII. The 1′,4′-trans-diol is formed from ABA, it is not a precursor." Functional Plant Biology 25, no. 6 (1998): 729. http://dx.doi.org/10.1071/pp98062.

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[14C]ABA fed to avocado fruit is known to be converted into the 1′,4′-trans-diol and [14C]1′,4′-trans-diol has been shown to be converted into ABA by several plant tissues. As a ‘cold trap’of trans-diol becomes labelled with 14C when [14C]mevalonate is converted into ABA, the trans-diol has been suggested to be the immediate precursor of ABA. This proposal has now been tested by feeding [5-14C,5-3H2]mevalonolactone to unripe avocado fruit and measuring the 3H :14C ratio in the ABA and in the 1′,4′-trans-diol isolated from the fruit after 16 h. Little labelled diol was present unless a ‘cold trap’ of unlabelled 1,4-trans-diol was added with the mevalonate. One 3H atom, derived from those at C-5 of mevalonate, would be expected at C-4′ of the diol, adjacent to the hydroxyl group, and another at C-5 of the side chain of the diol if the diol were a precursor of ABA (3H:14C ratio of 2:3). However, if the 4′-hydroxyl group had been oxidised to a ketone to form ABA, then the 3H atom at C-4′ of the diol would have been lost and the 3H:14C ratio would be expected to be 1:3. The normalised 3H : 14C ratios of ABA and 1′,4′-trans-diol biosynthesised from [14C,5-3H2]mevalonate were 0.915:3 and 0.844:3 respectively and after oxidation of the diol to ABA with MnO2 the ratio was 0.869:3 i.e. there was no 3H at C-4′ of the diol. These ratios are as expected for the trans-diol if it had been formed by reduction of ABA. This, and the absence of labelled diol in the fruit unless a ‘cold trap’was added, establishes that the 1′,4′-trans-diol is formed from ABA and it is not a precursor. The formation of the diols from newly synthesised labelled ABA in cell-free systems can be attributed to the addition to the homogenate of compounds with strong reducing potential. NADPH2+ (8.4 nmol) added to a mung bean seedling homogenate caused the reduction of (±)-[14C]ABA (0.37 nmol, 22.5 µCi/mol) to trans-diol (1189 dpm) whereas with NADP+ only 338 dpm were present in trans-diol. Glutathione (46 nmol) caused the formation of 1214 dpm while oxidised glutathione produced 638 dpm. Less 1′,4′-cis-diol was formed.

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36

WU, CONGJUN. "HIDDEN SYMMETRY AND QUANTUM PHASES IN SPIN-3/2 COLD ATOMIC SYSTEMS." Modern Physics Letters B 20, no. 27 (November 30, 2006): 1707–38. http://dx.doi.org/10.1142/s0217984906012213.

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Optical traps and lattices provide a new opportunity to study strongly correlated high spin systems with cold atoms. In this article, we review the recent progress on the hidden symmetry properties in the simplest high spin fermionic systems with hyperfine spin F=3/2, which may be realized with atoms of 132 Cs , 9 Be , 135 Ba , 137 Ba , and 201 Hg . A generic SO(5) or isomorphically, Sp(4) symmetry is proved in such systems with the s-wave scattering interactions in optical traps, or with the on-site Hubbard interactions in optical lattices. Various important features from this high symmetry are studied in the Fermi liquid theory, the mean field phase diagram, and the sign problem in quantum Monte-Carlo simulations. In the s-wave quintet Cooper pairing phase, the half-quantum vortex exhibits the global analogue of the Alice string and non-Abelian Cheshire charge properties in gauge theories. The existence of the quartetting phase, a four-fermion counterpart of the Cooper pairing phase, and its competition with other orders are studied in one-dimensional spin-3/2 systems. We also show that counter-intuitively quantum fluctuations in spin-3/2 magnetic systems are even stronger than those in spin-1/2 systems.

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37

Li, Jing, Qi Zhang, and Xi Chen. "Trigonometric protocols for shortcuts to adiabatic transport of cold atoms in anharmonic traps." Physics Letters A 381, no. 38 (October 2017): 3272–75. http://dx.doi.org/10.1016/j.physleta.2017.08.027.

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38

Davis, T. J. "2D magnetic traps for ultra-cold atoms: a simple theory using complex numbers." European Physical Journal D - Atomic, Molecular and Optical Physics 18, no. 1 (January 1, 2002): 27–36. http://dx.doi.org/10.1140/e10053-002-0003-x.

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39

KOUZAEV, GUENNADI A., and KARL J. SAND. "3D MULTICELL DESIGNS FOR REGISTERING OF BOSE–EINSTEIN CONDENSATE CLOUDS." Modern Physics Letters B 22, no. 25 (October 10, 2008): 2469–79. http://dx.doi.org/10.1142/s0217984908016777.

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In this letter, the results on the development and simulation of new three-dimensional nanotraps for cold dressed atoms are considered. The traps are the multi-cell structures built by crossed non-touching carbon or metallic nanotubes. The trapping effect is tuned by the DC and RF currents to confine the strong- or low-potential seeking atoms far enough from the areas of strong Casimir–Polder and spin-flip forces. It is supposed that the developed and simulated multi-cell structures are pertinent for catching the Bose–Einstein condensates to demonstrate the Josephson effect, and to enable the study of the entanglement of confined clouds in three-dimensional nano-cells.

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40

Kas, Milaim, Jacques Liévin, Nathalie Vaeck, and Jérôme Loreau. "Cold collisions of ${{\rm{C}}}_{2}^{-}$ with Li and Rb atoms in hybrid traps." Journal of Physics: Conference Series 1412 (January 2020): 062003. http://dx.doi.org/10.1088/1742-6596/1412/6/062003.

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41

González-Sánchez, L., F. Carelli, F. A. Gianturco, and R. Wester. "Collisional state-changing of OH− rotations by interaction with Rb atoms in cold traps." Chemical Physics 462 (November 2015): 111–18. http://dx.doi.org/10.1016/j.chemphys.2015.05.027.

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42

Torres-Herrera, Eduardo Jonathan, and Lea F. Santos. "Dynamical Detection of Level Repulsion in the One-Particle Aubry-André Model." Condensed Matter 5, no. 1 (January 20, 2020): 7. http://dx.doi.org/10.3390/condmat5010007.

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The analysis of level statistics provides a primary method to detect signatures of chaos in the quantum domain. However, for experiments with ion traps and cold atoms, the energy levels are not as easily accessible as the dynamics. In this work, we discuss how properties of the spectrum that are usually associated with chaos can be directly detected from the evolution of the number operator in the one-dimensional, noninteracting Aubry-André model. Both the quantity and the model are studied in experiments with cold atoms. We consider a single-particle and system sizes experimentally reachable. By varying the disorder strength within values below the critical point of the model, level statistics similar to those found in random matrix theory are obtained. Dynamically, these properties of the spectrum are manifested in the form of a dip below the equilibration point of the number operator. This feature emerges at times that are experimentally accessible. This work is a contribution to a special issue dedicated to Shmuel Fishman.

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Xian-Ming, Ji, and Yin Jian-Ping. "One- and Two-Dimensional Arrays of Double-Well Optical Traps for Cold Atoms or Molecules." Chinese Physics Letters 21, no. 12 (December 2004): 2399–402. http://dx.doi.org/10.1088/0256-307x/21/12/022.

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Fábián, Enikö Réka, and László Dévényi. "Hydrogen in the Plastic Deformed Steel." Materials Science Forum 537-538 (February 2007): 33–40. http://dx.doi.org/10.4028/www.scientific.net/msf.537-538.33.

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The solubility of hydrogen in iron and steels are affected by temperature and crystal structure. At lower temperatures (below about 400°C), the excess hydrogen, beyond that which is soluble (and therefore dissolved) interstitially, is retained in the steel in other sites commonly referred to as ”traps”. At room temperature, the dissolved hydrogen may be only a small fraction of the total hydrogen content. The movement of hydrogen in steel occurs by the migration of atoms through the lattice. The hydrogen diffusion takes place with interstitial mechanism. Trapping enhances the solubility of hydrogen but decreases the diffusivity. In practice hydrogen transmissibility is characterized by TH value. We have studied the effect of the cold rolling on the TH value for Al-killed low carbon enamelling-grade steel sheets. The microstructures of the samples were formed from ferrite, carbides and some non-metallic inclusions. Reducing the thickness of the steel sheets by cold rolling in carbides appears ruptures, microcavities, and the dislocation density increases in ferrite grains. Cold work increases the hydrogen permeation time. The average of TH values after hot rolling was 0.6; after about 72 % thickness reductions by cold rolling the average TH values was 101.4.

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Kondo, Yasushi, and Masayuki Matsuzaki. "Study of open systems with molecules in isotropic liquids." Modern Physics Letters B 32, no. 15 (May 24, 2018): 1830002. http://dx.doi.org/10.1142/s0217984918300028.

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We are interested in dynamics of a system in an environment, or an open system. Such phenomena as crossover from Markovian to non-Markovian relaxation and thermal equilibration are of our interest. Open systems have experimentally been studied with ultra cold atoms, ions in traps, optics, and cold electric circuits because well-isolated systems can be prepared here and thus the effects of environments can be controlled. We point out that some molecules solved in isotropic liquid are well isolated and thus they can also be employed for studying open systems in Nuclear Magnetic Resonance (NMR) experiments. First, we provide a short review on related phenomena of open systems that helps readers to understand our motivation. We, then, present two experiments as examples of our approach with molecules in isotropic liquids. Crossover from Markovian to non-Markovian relaxation was realized in one NMR experiment, while relaxation-like phenomena were observed in approximately isolated systems in the other.

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Ready, Adam J., Peter D. Haynes, Blazej Grabowski, David Rugg, and Adrian P. Sutton. "The role of molybdenum in suppressing cold dwell fatigue in titanium alloys." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 473, no. 2203 (July 2017): 20170189. http://dx.doi.org/10.1098/rspa.2017.0189.

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We test a hypothesis to explain why Ti-6242 is susceptible to cold dwell fatigue (CDF), whereas Ti-6246 is not. The hypothesis is that, in Ti-6246, substitutional Mo-atoms in α-Ti grains trap vacancies, thereby limiting creep relaxation. In Ti-6242, this creep relaxation enhances the loading of grains unfavourably oriented for slip and they subsequently fracture. Using density functional theory to calculate formation and binding energies between Mo-atoms and vacancies, we find no support for the hypothesis. In the light of this result, and experimental observations of the microstructures in these alloys, we agree with the recent suggestion (Qiu et al. 2014 Metall. Mater. Trans. A 45 , 6075–6087. ( doi:10.1007/s11661-014-2541-5 )) that Ti-6246 has a much smaller susceptibility to CDF because it has a smaller grain size and a more homogeneous distribution of grain orientations. We propose that the reduction of the susceptibility to CDF of Ti-6242 at temperatures above about 200° C is due to the activation of 〈 c + a 〉 slip in ‘hard’ grains, which reduces the loading of grain boundaries.

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Zinner, N. T. "Effective Potential for Ultracold Atoms at the Zero Crossing of a Feshbach Resonance." Journal of Atomic, Molecular, and Optical Physics 2012 (August 1, 2012): 1–9. http://dx.doi.org/10.1155/2012/241051.

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We consider finite-range effects when the scattering length goes to zero near a magnetically controlled Feshbach resonance. The traditional effective-range expansion is badly behaved at this point, and we therefore introduce an effective potential that reproduces the full T-matrix. To lowest order the effective potential goes as momentum squared times a factor that is well defined as the scattering length goes to zero. The potential turns out to be proportional to the background scattering length squared times the background effective range for the resonance. We proceed to estimate the applicability and relative importance of this potential for Bose-Einstein condensates and for two-component Fermi gases where the attractive nature of the effective potential can lead to collapse above a critical particle number or induce instability toward pairing and superfluidity. For broad Feshbach resonances the higher order effect is completely negligible. However, for narrow resonances in tightly confined samples signatures might be experimentally accessible. This could be relevant for suboptical wavelength microstructured traps at the interface of cold atoms and solid-state surfaces.

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Świerczyńska, Aleksandra, Dariusz Fydrych, and Jerzy Łabanowski. "The Effect of Welding Conditions on Diffusible Hydrogen Content in Deposited Metal." Solid State Phenomena 183 (December 2011): 193–200. http://dx.doi.org/10.4028/www.scientific.net/ssp.183.193.

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The primary limitation of weldability of high strength low alloy steel is susceptibility to cold cracking. The important reason of the formation of cold cracks, besides forming brittle structure and residual stresses, is the presence of diffusible hydrogen in welded joint. The most effective methods reducing the susceptibility to cold cracking are connected with decreasing the amount of potential hydrogen. This process may be carried out in technological (drying welding filler materials, preheating components) or in a metallurgical way (filler metals with austenitic structure, adding rare-earths elements to filler metals as traps for hydrogen atoms in steel). The possibility to minimize the amount of diffusible hydrogen by changing the welding parameters seems to be particularly interesting. The article presents the results of a literature survey and preliminary tests which set out effects of welding conditions on the amount of diffusible hydrogen in deposited metal. Experiments were conducted by using rutile coated electrodes which generate high contents of diffusible hydrogen in deposited metal. The amount of diffusible hydrogen was determined by a glycerin test. Eleven factors were considered: the electrode angle, the grinding of sample, the preheat temperature, the polarity of welding current, the welding current, the welding – cooling time, the electrode usage, the time of welding, the thickness of specimen, the welding – measurement time and thickness of electrode coating. All factors were optimized using a Plackett-Burman design to get the most relevant variables. The results of the preliminary tests indicate that appropriate choice of welding parameters may considerably reduce diffusible hydrogen in deposited metal. However, the range of parameters is limited by the necessity of providing stability of the welding process and obtaining required properties of the welded joint.

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Chauhan, Sadhana, Paola Barbieri, and Thomas K. Wood. "Oxidation of Trichloroethylene, 1,1-Dichloroethylene, and Chloroform by Toluene/o-Xylene Monooxygenase from Pseudomonas stutzeri OX1." Applied and Environmental Microbiology 64, no. 8 (August 1, 1998): 3023–24. http://dx.doi.org/10.1128/aem.64.8.3023-3024.1998.

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ABSTRACT Toluene/o-xylene monooxygenase (ToMO) fromPseudomonas stutzeri OX1, which oxidizes toluene ando-xylene, was examined for its ability to degrade the environmental pollutants trichloroethylene (TCE), 1,1-dichloroethylene (1,1-DCE), cis-1,2-DCE, trans-1,2-DCE, chloroform, dichloromethane, phenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, 2,3,5,6-tetrachlorophenol, and 2,3,4,5,6-pentachlorophenol.Escherichia coli JM109 that expressed ToMO from genes on plasmid pBZ1260 under control of the lac promoter degraded TCE (3.3 μM), 1,1-DCE (1.25 μM), and chloroform (6.3 μM) at initial rates of 3.1, 3.6, and 1.6 nmol/(min · mg of protein), respectively. Stoichiometric amounts of chloride release were seen, indicating mineralization (2.6, 1.5, and 2.3 Cl− atoms per molecule of TCE, 1,1-DCE, and chloroform, respectively). Thus, the substrate range of ToMO is extended to include aliphatic chlorinated compounds.

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Alves, Luis G., João F. Portel, Sílvia A. Sousa, Olga Ferreira, Stephanie Almada, Elisabete R. Silva, Ana M. Martins, and Jorge H. Leitão. "Investigations into the Structure/Antibacterial Activity Relationships of Cyclam and Cyclen Derivatives." Antibiotics 8, no. 4 (November 14, 2019): 224. http://dx.doi.org/10.3390/antibiotics8040224.

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A series of cyclam- and cyclen-derived salts are described in the present work; they were designed specifically to gain insights into their structure and antibacterial activity towards Staphylococcus aureus and Escherichia coli, used respectively, as Gram-positive and Gram-negative model organisms. The newly synthesized compounds are monosubstituted and trans-disubstituted tetraazamacrocycles that display benzyl, methylbenzyl, trifluoromethylbenzyl, or trifluoroethylbenzyl substituents appended on the nitrogen atoms of the macrocyclic ring. The results obtained show that the chemical nature, polarity, and substitution patterns of the benzyl groups, as well as the number of pendant arms, are critical parameters for the antibacterial activity of the cyclam-based salts. The most active compounds against both bacterial strains were the trans-disubstituted cyclam salts displaying CF3 groups in the para-position of the aromatic rings of the macrocyclic pendant arms. The analogous cyclen species presents a lower activity, revealing that the size of the macrocyclic backbone is an important requirement for the antibacterial activity of the tetraazamacrocycles. The nature of the anionic counterparts present on the salts was found to play a minor role in the antibacterial activity.

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Journal articles on the topic 'Cold atom traps'

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