Publications 20212022-04-05T19:03:14+02:00

Publications (2021)

Anionic states of C6Cl6 probed in electron transfer experiments

Authors: Kumar, S.; Kilich, T.; Labuda, M.; Garcia, G.; Limao-Vieira, P.


Publication date: 2021/12/22

DOI: 10.1039/d1cp04500h

Abstract: This is the first comprehensive investigation on the anionic species formed during collisions of fast neutral potassium (K) atoms with neutral hexachlorobenzene (C6Cl6) molecules in the laboratory frame range from 10 up to 100 eV. In such ion-pair formation experiments we also report a novel K+ energy loss spectrum obtained in the forward scattering giving evidence of the most accessible electronic states. The vertical electron affinity of (-3.76 +/- […]

Laboratory observation and astronomical search of 1-cyano propargyl radical, HCCCHCN

Authors: Cabezas, C.; Nakajima, M.; Chang, C. H.; Agundez, M.; Endo, Y.; Cernicharo, J.


Publication date: 2021/12/21

DOI: 10.1051/0004-6361/202142188

Abstract: Context. The reaction between carbon atoms and vinyl cyanide, CH2CHCN, is a formation route to interstellar 3-cyano propargyl radical, CH2C3N, a species that has recently been discovered in space. The 1-cyano propargyl radical (HC3HCN), an isomer of CH2C3N, is predicted to be produced in the same reaction at least twice more efficiently than CH2C3N. Hence, HC3HCN is a plausible candidate to be observed in space as well. […]

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Discovery of HCCCO and C5O in TMC-1 with the QUIJOTE line survey

Authors: Cernicharo, J.; Agundez, M.; Cabezas, C.; Tercero, B.; Marcelino, N.; Fuentetaja, R.; Pardo, J. R.; de Vicente, P.


Publication date: 2021/12/17

DOI: 10.1051/0004-6361/202142634

Abstract: We report on the detection, for the first time in space, of the radical HCCCO and of pentacarbon monoxide, C5O. The derived column densities are (1.6 +/- 0.2) x 10(11) cm(-2) and (1.5 +/- 0.2) x 10(10) cm(-2), respectively. We have also analysed the data for all the molecular species of the families HCnO and CnO within our QUIJOTE’s line survey. Upper […]

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Quantum variational optimization: The role of entanglement and problem hardness

Authors: Diez-Valle, Pablo; Porras, Diego; Garcia-Ripoll, Juan Jose


Publication date: 2021/12/16

DOI: 10.1103/PhysRevA.104.062426

Abstract: Quantum variational optimization has been posed as an alternative to solve optimization problems faster and at a larger scale than what classical methods allow. In this paper we study systematically the role of entanglement, the structure of the variational quantum circuit, and the structure of the optimization problem, in the success and efficiency of these algorithms. For this purpose, our study focuses on the variational quantum eigensolver (VQE) algorithm, as applied to quadratic […]

Photon-Mediated Stroboscopic Quantum Simulation of a Z(2) Lattice Gauge Theory

Authors: Armon, Tsafrir; Ashkenazi, Shachar; Garcia-Moreno, Gerardo; Gonzalez-Tudela, Alejandro; Zohar, Erez


Publication date: 2021/12/15

DOI: 10.1103/PhysRevLett.127.250501

Abstract: Quantum simulation of lattice gauge theories, aiming at tackling nonperturbative particle and condensed matter physics, has recently received a lot of interest and attention, resulting in many theoretical proposals as well as several experimental implementations. One of the current challenges is to go beyond 1 + 1 dimensions, where four-body (plaquette) interactions, not contained naturally in quantum simulating devices, appear. In this Letter, we propose a method to obtain them […]

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Mini Review: Quantum Confinement of Atomic and Molecular Clusters in Carbon Nanotubes

Authors: de Lara-Castells, Maria Pilar; Mitrushchenkov, Alexander O.


Publication date: 2021/12/08

DOI: 10.3389/fchem.2021.796890

Abstract: We overview our recent developments on a computational approach addressing quantum confinement of light atomic and molecular clusters (made of atomic helium and molecular hydrogen) in carbon nanotubes. We outline a multi-scale first-principles approach, based on density functional theory (DFT)-based symmetry-adapted perturbation theory, allowing an accurate characterization of the dispersion-dominated particle-nanotube interaction. Next, we describe a wave-function-based method, allowing rigorous fully coupled quantum calculations of the pseudo-nuclear bound states. The approach is illustrated […]

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Vibrational Energy Transfer in CO+N-2 Collisions: A Database for V-V and V-T/R Quantum-Classical Rate Coefficients

Authors: Hong, Qizhen; Bartolomei, Massimiliano; Coletti, Cecilia; Lombardi, Andrea; Sun, Quanhua; Pirani, Fernando


Publication date: 2021/12/01

DOI: 10.3390/molecules26237152

Abstract: Knowledge of energy exchange rate constants in inelastic collisions is critically required for accurate characterization and simulation of several processes in gaseous environments, including planetary atmospheres, plasma, combustion, etc. Determination of these rate constants requires accurate potential energy surfaces (PESs) that describe in detail the full interaction region space and the use of collision dynamics methods capable of including the most relevant quantum effects. In this work, we produce an […]

Evaluation of Recommended Cross Sections for the Simulation of Electron Tracks in Water

Authors: Garcia-Abenza, Adrian; Lozano, Ana I.; Oller, Juan C.; Blanco, Francisco; Gorfinkiel, Jimena D.; Limao-Vieira, Paulo; Garcia, Gustavo

Journal: ATOMS

Publication date: 2021/12/01

DOI: 10.3390/atoms9040098

Abstract: The accuracy of the most recent recommended cross sections dataset for electron scattering from gaseous H2O (J. Phys. Chem. Ref. Data 2021, 50, 023103) is probed in a joint experimental and computational study. Simulations of the magnetically confined electron transport through a gas cell containing H2O for different beam energies (3, 10 and 70 eV) and pressures (2.5 to 20.0 mTorr) have been performed by […]

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The Influence of the Symmetry of Identical Particles on Flight Times

Authors: Miret-Artes, Salvadorip; Dumont, Randall S.; Rivlin, Tom; Pollak, Eli

Journal: ENTROPY

Publication date: 2021/12/01

DOI: 10.3390/e23121675

Abstract: In this work, our purpose is to show how the symmetry of identical particles can influence the time evolution of free particles in the nonrelativistic and relativistic domains as well as in the scattering by a potential delta-barrier. For this goal, we consider a system of either two distinguishable or indistinguishable (bosons and fermions) particles. Two sets of initial conditions have been studied: different initial locations with the same momenta, and the same […]

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A complete data set for the simulation of electron transport through gaseous tetrahydrofuran in the energy range 1-100 eV

Authors: Garcia-Abenza, A.; Lozano, A., I; Alvarez, L.; Oller, J. C.; Blanco, F.; Stokes, P.; White, R. D.; de Urquijo, J.; Limao-Vieira, P.; Jones, D. B.; Brunger, M. J.; Garcia, G.


Publication date: 2021/12/01

DOI: 10.1140/epjd/s10053-021-00300-7

Abstract: A self-consistent data set, with all the necessary inputs for Monte Carlo simulations of electron transport through gaseous tetrahydrofuran (THF) in the energy range 1-100 eV, has been critically compiled in this study. Accurate measurements of total electron scattering cross sections (TCSs) from THF have been obtained, and considered […]

Formation of Phosphorus Monoxide (PO) in the Interstellar Medium: Insights from Quantum-chemical and Kinetic Calculations

Authors: Garcia de la Concepcion, Juan; Puzzarini, Cristina; Barone, Vincenzo; Jimenez-Serra, Izaskun; Roncero, Octavio


Publication date: 2021/12/01

DOI: 10.3847/1538-4357/ac1e94

Abstract: In recent years, phosphorus monoxide (PO), an important molecule for prebiotic chemistry, has been detected in star-forming regions and in the comet 67P/Churyumov-Gerasimenko. These studies have revealed that, in the interstellar medium (ISM), PO is systematically the most abundant P-bearing species, with abundances that are about one to three times greater than those derived for phosphorus nitride (PN), the second-most abundant P-containing molecule. The reason why PO is […]

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Unexpected benzene oxidation in collisions with superoxide anions

Authors: Guerra, Carlos; Kumar, Sarvesh; Aguilar-Galindo, Fernando; Diaz-Tendero, Sergio; Lozano, Ana, I; Mendes, Monica; Limao-Vieira, Paulo; Garcia, Gustavo


Publication date: 2021/11/30

DOI: 10.1038/s41598-021-02408-7

Abstract: Superoxide anions colliding with benzene molecules at impact energies from 200 to 900 eV are reported for the first time to form massive complexes. With the aid of quantum chemistry calculations, we propose a mechanism in which a sudden double ionization of benzene and the subsequent electrostatic attraction between the dication and the anion form a stable covalently bonded C6H6O2+ molecule, that evolves towards […]

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Three-Josephson junctions flux qubit couplings

Authors: Hita-Perez, Maria; Jauma, Gabriel; Pino, Manuel; Garcia-Ripoll, Juan Jose


Publication date: 2021/11/29

DOI: 10.1063/5.0069530

Abstract: We analyze the coupling of two flux qubits with a general many-body projector into the low-energy subspace. Specifically, we extract the effective Hamiltonians that controls the dynamics of two qubits when they are coupled via a capacitor and/or via a Josephson junction. While the capacitor induces a static charge coupling tunable by design, the Josephson junction produces a magnetic-like interaction easily tunable by replacing the junction with a superconducting quantum interference […]

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Photodissociation of the methyl radical: the role of nonadiabatic couplings in enhancing the variety of dissociation mechanisms

Authors: Garcia-Vela, A.


Publication date: 2021/11/24

DOI: 10.1039/d1cp03293c

Abstract: The nonadiabatic photodissociation dynamics of the CH3 (and CD3) radical from the 3p(z) and 3s Rydberg states is investigated by applying a one-dimensional (1D) wave packet model that uses recently calculated ab initio 1D electronic potential-energy curves and nonadiabatic couplings. Calculated predissociation lifetimes are found to be too long as compared to the experimental ones. The 1D dynamical model, however, is able to predict qualitatively and explain the fragmentation mechanisms that produce the hydrogen-fragment translational energy distributions […]

Qubit-photon bound states in topological waveguides with long-range hoppings

Authors: Vega, C.; Bello, M.; Porras, D.; Gonzalez-Tudela, A.


Publication date: 2021/11/19

DOI: 10.1103/PhysRevA.104.053522

Abstract: Quantum emitters interacting with photonic band-gap materials lead to the appearance of qubit-photon bound states that mediate decoherence-free, tunable emitter-emitter interactions. Recently, it has been shown that when these band gaps have a topological origin, like in the photonic Su-Schrieffer-Heeger (SSH) model, these qubit-photon bound states feature chiral shapes and certain robustness to disorder. In this paper, we consider a more general situation where the emitters interact with an extended SSH photonic […]

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