3,474 research outputs found

    [Review of] Carol Bruchac, Linda Hogan, Judith McDaniel, eds. The Stories We Hold Secret-Tales of Women\u27s Spiritual Development

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    The Stories We Hold Secret -- Tales of Women\u27s Spiritual Development is an anthology of thirty-one short fiction pieces written by and about women in America. These are not stories about extraterrestrial visits, enlightenment through gurus, or dramatic religious conversion; rather, these are stories of inner knowing, of our holy dailiness, as Linda Hogan says in the preface. The stories are as varied as women\u27s experience, from the quietness of a Native American woman cooking beans and cornbread in her kitchen to the tumult of a woman who for the first time becomes involved with a workers\u27 strike

    A simple approach to the correlation of rotovibrational states in four-atomic molecules

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    The problem of correlation between quantum states of four-atomic molecules in different geometrical configurations is reviewed in detail. A general, still simple rule is obtained which allows one to correlate states of a linear four-atomic molecule with those of any kind of non-linear four-atomic molecule.Comment: 16 pages (+8 figures), Postscript (ready to print!

    Optimal Topological Test for Degeneracies of Real Hamiltonians

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    We consider adiabatic transport of eigenstates of real Hamiltonians around loops in parameter space. It is demonstrated that loops that map to nontrivial loops in the space of eigenbases must encircle degeneracies. Examples from Jahn-Teller theory are presented to illustrate the test. We show furthermore that the proposed test is optimal.Comment: Minor corrections, accepted in Phys. Rev. Let

    CO oxidation at Pd(100): A first-principles constrained thermodynamics study

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    The possible formation of oxides or thin oxide films (surface oxides) on late transition metal surfaces is recently being recognized as an essential ingredient when aiming to understand catalytic oxidation reactions under technologically relevant gas phase conditions. Using the CO oxidation at Pd(100) as example, we investigate the composition and structure of this model catalyst surface over a wide range of (T,p)-conditions within a multiscale modeling approach where density-functional theory is linked to thermodynamics. The results show that under the catalytically most relevant gas phase conditions a thin surface oxide is the most stable "phase" and that the system is actually very close to a transition between this oxidic state and a reduced state in form of a CO covered Pd(100) surface.Comment: 13 pages including 7 figures; related publications can be found at http://www.fhi-berlin.mpg.de/th/th.htm

    Predicting and verifying transition strengths from weakly bound molecules

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    We investigated transition strengths from ultracold weakly bound 41K87Rb molecules produced via the photoassociation of laser-cooled atoms. An accurate potential energy curve of the excited state (3)1Sigma+ was constructed by carrying out direct potential fit analysis of rotational spectra obtained via depletion spectroscopy. Vibrational energies and rotational constants extracted from the depletion spectra of v'=41-50 levels were combined with the results of the previous spectroscopic study, and they were used for modifying an ab initio potential. An accuracy of 0.14% in vibrational level spacing and 0.3% in rotational constants was sufficient to predict the large observed variation in transition strengths among the vibrational levels. Our results show that transition strengths from weakly bound molecules are a good measure of the accuracy of an excited state potential.Comment: 7 pages, 7 figure

    On the Prospects for Laser Cooling of TlF

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    We measure the upper state lifetime and two ratios of vibrational branching fractions f_{v'v} on the B^{3}\Pi_{1}(v') - X^{1}\Sigma^{+}(v) transition of TlF. We find the B state lifetime to be 99(9) ns. We also determine that the off-diagonal vibrational decays are highly suppressed: f_{01}/f_{00} < 2x10^{-4} and f_{02}/f_{00} = 1.10(6)%, in excellent agreement with their predicted values of f_{01}/f_{00} < 8x10^{-4} and f_{02}/f_{00} = 1.0(2)% based on Franck-Condon factors calculated using Morse and RKR potentials. The implications of these results for the possible laser cooling of TlF and fundamental symmetries experiments are discussed.Comment: 5 pages, 2 figure

    Molecular Dipolar Crystals as High Fidelity Quantum Memory for Hybrid Quantum Computing

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    We study collective excitations of rotational and spin states of an ensemble of polar molecules, which are prepared in a dipolar crystalline phase, as a candidate for a high fidelity quantum memory. While dipolar crystals are formed in the high density limit of cold clouds of polar molecules under 1D and 2D trapping conditions, the crystalline structure protects the molecular qubits from detrimental effects of short range collisions. We calculate the lifetime of the quantum memory by identifying the dominant decoherence mechanisms, and estimate their effects on gate operations, when a molecular ensemble qubit is transferred to a superconducting strip line cavity (circuit QED). In the case rotational excitations coupled by dipole-dipole interactions we identify phonons as the main limitation of the life time of qubits. We study specific setups and conditions, where the coupling to the phonon modes is minimized. Detailed results are presented for a 1D dipolar chain

    Strong field ionization to multiple electronic states in water

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    High harmonic spectra show that laser-induced strong field ionization of water has a significant contribution from an inner-valence orbital. Our experiment uses the ratio of H2O and D2O high harmonic yields to isolate the characteristic nuclear motion of the molecular ionic states. The nuclear motion initiated via ionization of the highest occupied molecular orbital (HOMO) is small and is expected to lead to similar harmonic yields for the two isotopes. In contrast, ionization of the second least bound orbital (HOMO-1) exhibits itself via a strong bending motion which creates a significant isotope effect. We elaborate on this interpretation by simulating strong field ionization and high harmonic generation from the water isotopes using the time-dependent Schr\"odinger equation. We expect that this isotope marking scheme for probing excited ionic states in strong field processes can be generalized to other molecules

    A Spectroscopic Survey of Electronic Transitions of C6_6H, 13^{13}C6_6H, and C6_6D

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    Electronic spectra of C6_6H are measured in the 189502110018\,950-21\,100 cm1^{-1} domain using cavity ring-down spectroscopy of a supersonically expanding hydrocarbon plasma. In total, 19 (sub)bands of C6_6H are presented, all probing the vibrational manifold of the B2Π^2\Pi electronically excited state. The assignments are guided by electronic spectra available from matrix isolation work, isotopic substitution experiments (yielding also spectra for 13^{13}C6_6H and C6_6D), predictions from ab initio calculations as well as rotational fitting and vibrational contour simulations using the available ground state parameters as obtained from microwave experiments. Besides the 0000_0^0 origin band, three non-degenerate stretching vibrations along the linear backbone of the C6_6H molecule are assigned: the ν6\nu_6 mode associated with the C-C bond vibration and the ν4\nu_4 and ν3\nu_3 modes associated with C\equivC triple bonds. For the two lowest ν11\nu_{11} and ν10\nu_{10} bending modes, a Renner-Teller analysis is performed identifying the μ2Σ\mu^2\Sigma(ν11\nu_{11}) and both μ2Σ\mu^2\Sigma(ν10\nu_{10}) and κ2Σ\kappa^2\Sigma(ν10\nu_{10}) components. In addition, two higher lying bending modes are observed, which are tentatively assigned as μ2Σ\mu^2\Sigma(ν9\nu_9) and μ2Σ\mu^2\Sigma(ν8\nu_8) levels. In the excitation region below the first non-degenerate vibration (ν6\nu_6), some 2Π2Π^2\Pi-^{2}\Pi transitions are observed that are assigned as even combination modes of low-lying bending vibrations. The same holds for a 2Π2Π^2\Pi-^{2}\Pi transition found above the ν6\nu_6 level. From these spectroscopic data and the vibronic analysis a comprehensive energy level diagram for the B2Π^2\Pi state of C6_6H is derived and presented.Comment: Accepted for publication in The Journal of Physical Chemistry A (26 July 2016
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