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Related papers: Molecular hydrogen in silicon: A path-integral sim…

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We report on an electron spin resonance study of atomic hydrogen stabilized in a solid Ne matrices carried out at a high field of 4.6 T and temperatures below 1 K. The films of Ne, slowly deposited on the substrate at the temperature…

We investigate thermal rectification in nanoporous silicon using a semi-classical Monte Carlo (MC) simulation method. We consider geometrically asymmetric nanoporous structures, and investigate the combined effects of porosity, inter-pore…

Materials Science · Physics 2019-11-18 Dhritiman Chakraborty , Joshua Brooke , Nick C S Hulse , Neophytos Neophytou

Incorporation mechanisms of H_2 in silica glass were studied with Raman and infrared (IR) microspectroscopy. Hydrogenated samples were prepared at temperatures between 800 deg C and 955 deg C at 2 kbar total pressure. Hydrogen fugacities…

Geophysics · Physics 2016-08-16 Burkhard C. Schmidt , François Holtz , Jean-Michel Bény

We present the results from three dimensional hydrodynamical simulations of decaying high-speed turbulence in dense molecular clouds. We compare our results, which include a detailed cooling function, molecular hydrogen chemistry and a…

Astrophysics · Physics 2009-11-07 Georgi Pavlovski , Michael D. Smith , Mordecai-Mark Mac Low , Alexander Rosen

Recently, vacancy-related spin defects in silicon carbide (SiC) have been demonstrated to be potentially suitable for versatile quantum interface building and scalable quantum network construction. Significant efforts have been undertaken…

We measure and theoretically determine the effect of molecular rotational splitting on Zeeman relaxation rates in collisions of cold Triplet-Sigma molecules with helium atoms in a magnetic field. All four stable isotopomers of the imidogen…

We present a multiple time step algorithm for hybrid path integral Monte Carlo simulations involving rigid linear rotors. We show how to calculate the quantum torques needed in the simulation from the rotational density matrix, for which we…

Statistical Mechanics · Physics 2007-05-23 G. Garberoglio , J. K. Johnson

In order to study the heating process of water by the microwaves of 2.5-20GHz frequencies, we have performed molecular dynamics simulations by adopting a non-polarized water model that have fixed point charges on rigid-body molecules. All…

Materials Science · Physics 2009-11-11 Motohiko Tanaka , Motoyasu Sato

On the basis of density functional calculations and using Bader's atom in molecule theory, this article presents quantitative microscopic analyses on the bonding properties of amorphous silicon (a-Si) which could reflect in the observable…

Materials Science · Physics 2019-04-11 Zahra Nourbakhsh , Hadi Akbarzadeh

A roughly constant temperature over a wide range of densities is maintained in molecular clouds through radiative heating and cooling. An isothermal equation of state is therefore frequently employed in molecular cloud simulations. However,…

Astrophysics · Physics 2009-11-11 G. Pavlovski , M. D. Smith , M. -M. Mac Low

Hybrid ion-atom systems provide an excellent platform for studies of state-resolved quantum chemistry at low temperatures, where quantum effects may be prevalent. Here we study theoretically the process of vibrational relaxation of an…

Atomic Physics · Physics 2020-04-01 Krzysztof Jachymski , Florian Meinert

Ab initio random structure searching with density functional theory was used to determine the zero-temperature structures of atomic metallic hydrogen from 500 GPa to 5 TPa. Including zero point motion in the harmonic approximation, we…

Materials Science · Physics 2015-05-20 Jeffrey M. McMahon , David M. Ceperley

Thermal atomic vibrations in amorphous solids can be distinguished by whether they propagate as elastic waves or do not propagate due to lack of atomic periodicity. In a-Si, prior works concluded that non-propagating waves are the dominant…

Disordered Systems and Neural Networks · Physics 2018-01-17 Jaeyun Moon , Benoit Latour , Austin Minnich

The structural and electronic properties of amorphous silicon ($a$-Si) are investigated by first-principles calculations based on the density-functional theory (DFT), focusing on the intrinsic structural defects. By simulated melting and…

Materials Science · Physics 2017-10-11 Yoritaka Furukawa , Yu-ichiro Matsushita

We have studied solid hydrogen up to pressures of 300 GPa and temperatures of 350 K using density functional theory methods and have found "mixed structures" that are more stable than those predicted earlier. Mixed structures consist of…

Materials Science · Physics 2012-06-20 Chris J. Pickard , Miguel Martinez-Canales , Richard J. Needs

The structural features of the interface between the cystalline and amorphous phases of Si solid are studied in simulations based on a combination of empirical interatomic potentials and a nonorthogonal tight-binding model. The…

Materials Science · Physics 2009-10-31 N. Bernstein , M. J. Aziz , E. Kaxiras

We present a design for an atomic synchrotron consisting of 40 hybrid magnetic hexapole lenses arranged in a circle. We show that for realistic parameters, hydrogen atoms with a velocity up to 600 m/s can be stored in a 1-meter diameter…

Atomic Physics · Physics 2015-01-26 Aernout P P van der Poel , Katrin Dulitz , Timothy P Softley , Hendrick L Bethlem

The detailed distribution and kinematics of the atomic and the CO-bright molecular hydrogen in the disc of the Milky Way inside the Solar circle are derived under the assumptions of axisymmetry and pure circular motions. We divide the…

Astrophysics of Galaxies · Physics 2017-11-22 A. Marasco , F. Fraternali , J. M. van der Hulst , T. Oosterloo

Experiments and computer simulations have shown that the melt-ing temperature of solid hydrogen drops with pressure above about 65 GPa, suggesting that a liquid state might exist at low temperatures. It has also been suggested that this low…

Spatiotemporal dynamics of electron-hole pairs locally excited in a silicon-on-insulator structure by indirect interband absorption are studied by measuring differential transmission caused by free-carrier absorption of a probe pulse tuned…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Hui Zhao