The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
John M Doyle - One of the best experts on this subject based on the ideXlab platform.
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Continuous probing of cold complex molecules with infrared frequency comb spectroscopy
Nature, 2016Co-Authors: Ben Spaun, John M Doyle, David Patterson, P. Bryan Changala, Bryce J. Bjork, Oliver H. Heckl, Jun YeAbstract:Combining cavity-enhanced direct frequency comb spectroscopy with buffer Gas Cooling enables rapid collection of well-resolved infrared spectra for molecules such as nitromethane, naphthalene and adamantane, confirming the value of the combined approach for studying much larger and more complex molecules than have been probed so far. High-resolution infrared spectroscopy is well suited to the study of the structure and dynamics of small molecules, but becomes impractical for larger and more complex systems. Jun Ye and colleagues have used a combination of cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) and buffer Gas Cooling to produce well-resolved infrared spectra for significantly larger and more complex molecules than have been probed so far using conventional methods. Using CE-DFCS, spectra were obtained for nitromethane, naphthalene and adamantane. For more than half a century, high-resolution infrared spectroscopy has played a crucial role in probing molecular structure and dynamics. Such studies have so far been largely restricted to relatively small and simple systems, because at room temperature even molecules of modest size already occupy many millions of rotational/vibrational states, yielding highly congested spectra that are difficult to assign. Targeting more complex molecules requires methods that can record broadband infrared spectra (that is, spanning multiple vibrational bands) with both high resolution and high sensitivity. However, infrared spectroscopic techniques have hitherto been limited either by narrow bandwidth and long acquisition time^ 1 , or by low sensitivity and resolution^ 2 . Cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) combines the inherent broad bandwidth and high resolution of an optical frequency comb with the high detection sensitivity provided by a high-finesse enhancement cavity^ 3 , 4 , but it still suffers from spectral congestion^ 5 . Here we show that this problem can be overcome by using buffer Gas Cooling^ 6 to produce continuous, cold samples of molecules that are then subjected to CE-DFCS. This integration allows us to acquire a rotationally resolved direct absorption spectrum in the C–H stretching region of nitromethane, a model system that challenges our understanding of large-amplitude vibrational motion^ 7 , 8 , 9 . We have also used this technique on several large organic molecules that are of fundamental spectroscopic and astrochemical relevance, including naphthalene^ 10 , adamantane^ 11 and hexamethylenetetramine^ 12 . These findings establish the value of our approach for studying much larger and more complex molecules than have been probed so far, enabling complex molecules and their kinetics to be studied with orders-of-magnitude improvements in efficiency, spectral resolution and specificity.
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intense atomic and molecular beams via neon buffer Gas Cooling
New Journal of Physics, 2009Co-Authors: David Patterson, Julia Rasmussen, John M DoyleAbstract:We realize a continuous, intense, cold molecular and atomic beam source based on buffer-Gas Cooling. Hot vapor (up to 600 K) from an oven is mixed with cold (15 K) neon buffer Gas, and then emitted into a high-flux beam. The novel use of cold neon as a buffer Gas produces a forward velocity distribution and low-energy tail that is comparable to much colder helium-based sources. We expect this source to be trivially generalizable to a very wide range of atomic and molecular species with significant vapor pressure below 1000 K. The source has properties that make it a good starting point for laser Cooling of molecules or atoms, cold collision studies, trapping, or nonlinear optics in buffer-Gas-cooled atomic or molecular Gases. A continuous guided beam of cold deuterated ammonia with a flux of 3×1011 ND3 molecules s−1 and a continuous free-space beam of cold potassium with a flux of 1×1016 K atoms s−1 are realized.
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realization of coherent optically dense media via buffer Gas Cooling
Physical Review A, 2009Co-Authors: A S Zibrov, John M Doyle, Mikhail D. Lukin, David Patterson, Alexey V. Gorshkov, Tao Hong, Mara PrentissAbstract:We demonstrate that buffer-Gas Cooling combined with laser ablation can be used to create coherent optical media with high optical depth and low Doppler broadening that offers metastable states with low collisional and motional decoherence. Demonstration of this generic technique opens pathways to coherent optics with a large variety of atoms and molecules. We use helium buffer Gas to cool $^{87}\mathrm{Rb}$ atoms to below $7\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ and slow atom diffusion to the walls. Electromagnetically induced transparency in this medium allows for 50% transmission in a medium with initial optical depth $Dg70$ and for slow pulse propagation with large delay-bandwidth products. In the high-$D$ regime, we observe high-contrast spectrum oscillations due to efficient four-wave mixing.
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buffer Gas Cooling of nh via the beam loaded buffer Gas method
European Physical Journal D, 2004Co-Authors: Dima Egorov, Edem Tsikata, Wesley C Campbell, Bretislav Friedrich, S E Maxwell, L D Van Buuren, John M DoyleAbstract:NH radicals from a molecular beam are cooled using a novel beam-loaded buffer Gas method. The radicals are produced in a glow discharge beam source and injected into cryogenic helium Gas. Up to 10 12 molecules in their ground electronic, vibrational, and rotational state are detected in the buffer Gas and translational temperatures under 6 K are achieved. The Cooling method presented is general and can be applied to any molecules in a molecular beam. PACS. 33.80.Ps Optical Cooling of molecules; trapping - 34.50.Ez Rotational and vibrational energy transfer - 39.10.+j Atomic and molecular beam sources and techniques
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
J G E Harris - One of the best experts on this subject based on the ideXlab platform.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
Nathan Brahms - One of the best experts on this subject based on the ideXlab platform.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
S V Nguyen - One of the best experts on this subject based on the ideXlab platform.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
R A Michniak - One of the best experts on this subject based on the ideXlab platform.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
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buffer Gas Cooling and trapping of atoms with small effective magnetic moments
EPL, 2004Co-Authors: R A Michniak, S V Nguyen, Nathan Brahms, J G E Harris, Wolfgang Ketterle, John M DoyleAbstract:We have extended buffer Gas Cooling to trap atoms with small effective magnetic moments μeff. For μeff ≥ 3μB, 1012 atoms were buffer Gas cooled, trapped, and thermally isolated in ultra high vacuum with roughly unit efficiency. For μeff < 3μB, the fraction of atoms remaining after full thermal isolation was limited by two processes: wind from the rapid removal of the buffer Gas and desorbing helium films. In our current apparatus we trap atoms with μeff ≥ 1μB, and thermally isolate atoms with μeff ≥ 1.8μB. This triples the number of atomic species which can be buffer Gas cooled and trapped in thermal isolation. Extrapolation of our results and simulations of the loss processes indicate that it is possible to trap and evaporatively cool 1μB atoms using buffer Gas Cooling.
