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

Publications (2021)

The growth of density perturbations in the last similar to 10 billion years from tomographic large-scale structure data

Authors: Garcia-Garcia, Carlos; Ruiz-Zapatero, Jaime; Alonso, David; Bellini, Emilio; Ferreira, Pedro G.; Mueller, Eva-Maria; Nicola, Andrina; Ruiz-Lapuente, Pilar

Journal: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

Publication date: 2021/10/01

DOI: 10.1088/1475-7516/2021/10/030

Abstract: In order to investigate the origin of the ongoing tension between the amplitude of matter fluctuations measured by weak lensing experiments at low redshifts and the value inferred from the cosmic microwave background anisotropies, we reconstruct the evolution of this amplitude from z similar to 2 using existing large-scale structure data. To do so, we decouple the linear growth of […]

Theoretical priors in scalar-tensor cosmologies: Shift-symmetric Horndeski models

Authors: Traykova, Dina; Bellini, Emilio; Ferreira, Pedro G.; Garcia-Garcia, Carlos; Noller, Johannes; Zumalacarregui, Miguel

Journal: PHYSICAL REVIEW D

Publication date: 2021/10/01

DOI: 10.1103/PhysRevD.104.083502

Abstract: Attempts at constraining theories of late time accelerated expansion often assume broad priors for the parameters in their phenomenological description. Focusing on shift-symmetric scalar-tensor theories with standard gravitational wave speed, we show how a more careful analysis of their dynamical evolution leads to much narrower priors. In doing so, we propose a simple and accurate parametrization of these theories, capturing the redshift dependence of the equation of […]

A Path Integral Molecular Dynamics Simulation of a Harpoon-Type Redox Reaction in a Helium Nanodroplet

Authors: Castillo-Garcia, Alvaro; Hauser, Andreas W.; De Lara-Castells, Maria Pilar; Villarreal, Pablo

Journal: MOLECULES

Publication date: 2021/10/01

DOI: 10.3390/molecules26195783

Abstract: We present path integral molecular dynamics (PIMD) calculations of an electron transfer from a heliophobic Cs2 dimer in its (3 sigma u) state, located on the surface of a He droplet, to a heliophilic, fully immersed C60 molecule. Supported by electron ionization mass spectroscopy measurements (Renzler et al., J. Chem. Phys. 2016, 145, 181101), this spatially quenched reaction was characterized as a harpoon-type or long-range electron transfer in a previous high-level […]

Automatic design of quantum feature maps

Authors: Altares-Lopez, Sergio; Ribeiro, Angela; Garcia-Ripoll, Juan Jose

Journal: QUANTUM SCIENCE AND TECHNOLOGY

Publication date: 2021/10/01

DOI: 10.1088/2058-9565/ac1ab1

Abstract: We propose a new technique for the automatic generation of optimal ad-hoc ansatze for classification by using quantum support vector machine. This efficient method is based on non-sorted genetic algorithm II multiobjective genetic algorithms which allow both maximize the accuracy and minimize the ansatz size. It is demonstrated the validity of the technique by a practical example with a non-linear dataset, interpreting the resulting circuit and its outputs. We also show other […]

Quantum electrodynamics in anisotropic and tilted Dirac photonic lattices

Authors: Redondo-Yuste, Jaime; Blanco de Paz, Maria; Huidobro, Paloma A.; Gonzalez-Tudela, Alejandro

Journal: NEW JOURNAL OF PHYSICS

Publication date: 2021/10/01

DOI: 10.1088/1367-2630/ac27e0

Abstract: One of the most striking predictions of quantum electrodynamics is that vacuum fluctuations of the electromagnetic field can lead to spontaneous emission of atoms as well as photon-mediated interactions among them. Since these processes strongly depend on the nature of the photonic bath, a current burgeoning field is the study of their modification in the presence of photons with non-trivial energy dispersions, e.g. the ones confined in photonic […]

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Non-equilibrium coupling of a quartz resonator to ions for Penning-trap fast resonant detection

Authors: Berrocal, Joaquin; Lohse, Steffen; Dominguez, Francisco; Gutierrez, Manuel J.; Fernandez, Francisco J.; Block, Michael; Garcia-Ripoll, Juan J.; Rodriguez, Daniel

Journal: QUANTUM SCIENCE AND TECHNOLOGY

Publication date: 2021/10/01

DOI: 10.1088/2058-9565/ac01bc

Abstract: The coherent coupling between a quartz electro-mechanical resonator at room temperature and trapped ions in a 7 T Penning trap has been demonstrated for the first time. The signals arising from the coupling remain for integration times in the orders of seconds. From the measurements carried out, we demonstrate that the coupling allows detecting the reduced-cyclotron frequency (nu(+)) within times […]

DEATHSTAR: nearby AGB stars with the Atacama Compact Array II. CO envelope sizes and asymmetries: the S-type stars

Authors: Andriantsaralaza, M.; Ramstedt, S.; Vlemmings, W. H. T.; Danilovich, T.; De Beck, E.; Groenewegen, M. A. T.; Hofner, S.; Kerschbaum, F.; Khouri, T.; Lindqvist, M.; Maercker, M.; Olofsson, H.; Quintana-Lacaci, G.; Saberi, M.; Sahai, R.; Zijlstra, A.

Journal: ASTRONOMY & ASTROPHYSICS

Publication date: 2021/09/21

DOI: 10.1051/0004-6361/202140952

Abstract: Aims. We aim to constrain the sizes of, and investigate deviations from spherical symmetry in, the CO circumstellar envelopes (CSEs) of 16 S-type stars, along with an additional 7 and 4 CSEs of C-type and M-type AGB stars, respectively. Methods. We map the […]

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Encapsulation of a Water Molecule inside C-60 Fullerene: The Impact of Confinement on Quantum Features

Authors: Carrillo-Bohorquez, Orlando; Valdes, Alvaro; Prosmiti, Rita

Journal: JOURNAL OF CHEMICAL THEORY AND COMPUTATION

Publication date: 2021/09/14

DOI: 10.1021/acs.jctc.1c00662

Abstract: We introduce an efficient quantum fully coupled computational scheme within the multiconfiguration time-dependent Hartree (MCTDH) approach to handle the otherwise extremely costly computations of translational-rotational-vibrational states and energies of light-molecule endofullenes. Quantum calculations on energy levels are reported for a water molecule inside C-60 fullerene by means of such a systematic approach that includes all nine degrees of freedom of H2O@C-60 and does not consider restrictions above them. The potential energy […]

LiCl Photodissociation on Graphene: A Photochemical Approach to Lithium Intercalation

Authors: Azpeitia, Jon; Merino, Pablo; Ruiz-Gomez, Sandra; Foerster, Michael; Aballe, Lucia; Garcia-Hernandez, Mar; Angel Martin-Gago, Jose; Palacio, Irene

Journal: ACS APPLIED MATERIALS & INTERFACES

Publication date: 2021/09/08

DOI: 10.1021/acsami.1c11654

Abstract: The interest in the research of the structural and electronic properties between graphene and lithium has bloomed since it has been proven that the use of graphene as an anode material in lithium-ion batteries ameliorates their performance and stability. Here, we investigate an alternative route to intercalate lithium underneath epitaxially grown graphene on iridium by means of photon irradiation. We grow […]

Atomic-Scale Structural Fluctuations of a Plasmonic Cavity

Authors: Roslawska, Anna; Merino, Pablo; Grewal, Abhishek; Leon, Christopher C.; Kuhnke, Klaus; Kern, Klaus

Journal: NANO LETTERS

Publication date: 2021/09/08

DOI: 10.1021/acs.nanolett.1c02207

Abstract: Optical spectromicroscopies, which can reach atomic resolution due to plasmonic enhancement, are perturbed by spontaneous intensity modifications. Here, we study such fluctuations in plasmonic electroluminescence at the single-atom limit profiting from the precision of a low-temperature scanning tunneling microscope. First, we investigate the influence of a controlled single-atom transfer from the tip to the sample on the plasmonic properties of the junction. Next, we form a well-defined atomic […]

Magnesium radicals MgC5N and MgC6H in IRC+10216

Authors: Pardo, J. R.; Cabezas, C.; Fonfria, J. P.; Agundez, M.; Tercero, B.; de Vicente, P.; Guelin, M.; Cernicharo, J.

Journal: ASTRONOMY & ASTROPHYSICS

Publication date: 2021/08/31

DOI: 10.1051/0004-6361/202141671

Abstract: After the previous discovery of MgC3N and MgC4H in IRC +10216, a deeper Q-band (31.0-50.3 GHz) integration on this source had revealed two additional series of harmonically related doublets that we assigned on the basis of quantum mechanical calculations to the larger radicals MgC5N and MgC6H. The results presented here extend and confirm previous results on magnesium-bearing molecules in IRC +10216. […]

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Versatile Atomic Magnetometry Assisted by Bayesian Inference

Authors: Puebla, R.; Ban, Y.; Haase, J. F.; Plenio, M. B.; Paternostro, M.; Casanova, J.

Journal: PHYSICAL REVIEW APPLIED

Publication date: 2021/08/25

DOI: 10.1103/PhysRevApplied.16.024044

Abstract: Quantum sensors typically translate external fields into a periodic response whose frequency is then determined by analyses performed in Fourier space. This allows for a linear inference of the parameters that characterize external signals. In practice, however, quantum sensors are able to detect fields only in a narrow range of amplitudes and frequencies. A departure from this range, as well as the presence of significant noise […]

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Discovery of benzyne, o-C6H4, in TMC-1 with the QUIJOTE line survey

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

Journal: ASTRONOMY & ASTROPHYSICS

Publication date: 2021/08/18

DOI: 10.1051/0004-6361/202141660

Abstract: We report the detection, for the first time in space, of a new non-functionalised hydrocarbon cycle in the direction of TMC-1: o-C6H4 (ortho-benzyne). We derive a column density for this hydrocarbon cycle of (5.0 +/- 1.0) x 10(11) cm(-2). The abundance of this species is around 30 times lower than that of cyclopentadiene and indene. We compare the abundance of benzyne […]

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Observation and calibration strategies for large-scale multi-beam velocity-resolved mapping of the [CII] emission in the Orion molecular cloud

Authors: Higgins, R.; Kabanovic, S.; Pabst, C.; Teyssier, D.; Goicoechea, J. R.; Berne, O.; Chambers, E.; Wolfire, M.; Suri, S. T.; Buchbender, C.; Okada, Y.; Mertens, M.; Parikka, A.; Aladro, R.; Richter, H.; Gusten, R.; Stutzki, J.; Tielens, A. G. G. M.

Journal: ASTRONOMY & ASTROPHYSICS

Publication date: 2021/08/12

DOI: 10.1051/0004-6361/202039621

Abstract: Context. The [CII] 158 mu m far-infrared fine-structure line is one of the dominant cooling lines of the star-forming interstellar medium. Hence [CII] emission originates in and thus can be used to trace a range of ISM processes. Velocity-resolved […]

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Electron-impact excitation of the (4d(10)5s) S-2(1/2)-> (4d(9)5s(2)) D-2(3/2) and (4d(10)6s) S-2(1/2) ->(4d(10)6s) 2S(1/ 2) transitions in silver: Experiment and theory

Authors: Marinkovic, B. P.; Tosic, S. D.; Sevic, D.; McEachran, R. P.; Blanco, F.; Garcia, G.; Brunger, M. J.

Journal: PHYSICAL REVIEW A

Publication date: 2021/08/10

DOI: 10.1103/PhysRevA.104.022808

Abstract: We present angle-differential and angle-integrated cross sections for electron-impact excitation of the (4d(10)5s) S-2(1/ 2) -> (4d(9)5s(2)) D-2(3/ 2) and (4d(10)5s) S-2(1/ 2) ->(4d(10)6s) S-2(1/ 2) transitions in atomic silver. Experimental data for four incident electron energies between 10 and 60 eV are compared with predictions from our relativistic distorted wave (RDW) and nonrelativistic atomic optical potential models. Agreement between our measured […]

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