Publications sorted by date descending
Quantum control of tunable-coupling transmons using dynamical invariants of motion
Authors: Espinos, H.; Panadero, I; Garcia-Ripoll, J. J.; Torrontegui, E.
Journal: QUANTUM SCIENCE AND TECHNOLOGY
Publication date: 2023/04/01
Abstract: We analyze the implementation of a fast nonadiabatic CZ gate between two transmon qubits with tunable coupling. The gate control method is based on a theory of dynamical invariants which leads to reduced leakage and robustness against decoherence. The gate is based on a description of the resonance between the |11) and |20) using an effective Hamiltonian with the six lowest energy states. A modification of the protocol allows us […]
Parallel tomography of quantum non-demolition measurements in multi-qubit devices
Authors: Pereira, L.; Garcia-Ripoll, J. J.; Ramos, T.
Journal: NPJ QUANTUM INFORMATION
Publication date: 2023/03/04
Abstract: An efficient characterization of QND measurements is an important ingredient toward certifying and improving the performance and scalability of quantum processors. In this work, we introduce a parallel tomography of QND measurements that addresses single- and two-qubit readout on a multi-qubit quantum processor. We provide an experimental demonstration of the tomographic protocol on a 7-qubit IBM-Q device, characterizing the quality of conventional qubit readout as well as generalized measurements such as parity or […]
Vibrational, non-adiabatic and isotopic effects in the dynamics of the H-2 + H2?+H3+ + H reaction: application to plasma modelling
Authors: del Mazo-Sevillano, P.; Felix-Gonzalez, D.; Aguado, A.; Sanz-Sanz, C.; Kwon, D. -H.; Roncero, O.
Journal: MOLECULAR PHYSICS
Publication date: 2023/03/01
Abstract: The title reaction is studied using a quasi-classical trajectory method for collision energies between 0.1 meV and 10 eV, considering the vibrational excitation of H-2(+) reactant. A new potential energy surface is developed based on a Neural Network many body correction of a triatomics-in-molecules potential, which significantly improves the accuracy of the potential up to energies of 17 eV, higher than in other previous fits. The effect […]
Seminario IFF #1/2023 – Dr. Tomás González Lezana – “Simulaciones Moleculares en Agregados de Helio”
¡Comenzamos con fuerza el ciclo de seminarios del IFF en 2023! En esta ocasión, nuestro compañero Tomás González Lezana, director del Departamento de Procesos Atómicos, Moleculares y en Superficies (PAMS) del IFF, impartirá una charla de título “Simulaciones Moleculares en Agregados de Helio” el próximo lunes 27 de febrero en la Sala de Conferencias de Serrano 121 a las 12.00h. ¡Os esperamos!
Gas kinematics around filamentary structures in the Orion B cloud
Authors: Gaudel, Mathilde; Orkisz, Jan H.; Gerin, Maryvonne; Pety, Jerome; Roueff, Antoine; Marchal, Antoine; Levrier, Francois; Miville-Deschenes, Marc-Antoine; Goicoechea, Javier R.; Roueff, Evelyne; Le Petit, Franck; Magalhaes, Victor de Souza; Palud, Pierre; Santa-Maria, Miriam G.; Vono, Maxime; Bardeau, Sebastien; Bron, Emeric; Chainais, Pierre; Chanussot, Jocelyn; Gratier, Pierre; Guzman, Viviana; Hughes, Annie; Kainulainen, Jouni; Languignon, David; Le Bourlot, Jacques; Liszt, Harvey; Oberg, Karin; Peretto, Nicolas; Sievers, Albrecht; Tremblin, Pascal
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2023/02/07
Abstract: Context. Understanding the initial properties of star-forming material and how they affect the […]
The stochastic wave function method for diffusion of alkali atoms on metallic surfaces
Authors: Torres-Miyares, E. E.; Ward, D. J.; Rojas-Lorenzo, G.; Rubayo-Soneira, J.; Allison, W.; Miret-Artes, S.
Journal: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publication date: 2023/02/05
Abstract: The stochastic wave function method is proposed to study the diffusion regimes of alkali atoms on metallic surfaces. The Lindblad approach, based on the microscopic Hamiltonian information in the Caldeira-Leggett model, is presented and numerical calculations of the dynamics are carried out to characterize surface diffusion for two different systems: Na-Cu(111) and Li-Cu(111). Calculations of the intermediate scattering function for an isolated adsorbate are compared, […]
Quantum Approximate Optimization Algorithm Pseudo-Boltzmann States
Authors: Diez-Valle, Pablo; Porras, Diego; Garcia-Ripoll, Juan Jose
Journal: PHYSICAL REVIEW LETTERS
Publication date: 2023/02/02
Abstract: In this Letter, we provide analytical and numerical evidence that the single-layer quantum approximate optimization algorithm on universal Ising spin models produces thermal-like states. We find that these pseudo-Boltzmann states can not be efficiently simulated on classical computers according to the general state-of-the-art condition that ensures rapid mixing for Ising models. Moreover, we observe that the temperature depends on a hidden universal correlation between the energy of a state and the covariance of […]
The Binary and the Disk: The Beauty is Found within NGC3132 with JWST
Authors: Sahai, Raghvendra; Bujarrabal, Valentin; Quintana-Lacaci, Guillermo; Reindl, Nicole; Van de Steene, Griet; Contreras, Carmen Sanchez; Ressler, Michael E.
Journal: ASTROPHYSICAL JOURNAL
Publication date: 2023/02/01
Abstract: The planetary nebula (PN) NGC 3132 is a striking example of the dramatic but poorly understood mass-loss phenomena that (1-8) M (circle dot) stars undergo during their death throes as they evolve into white dwarfs (WDs). From an analysis of JWST multiwavelength (0.9-18 mu m) imaging of NGC 3132, we report the discovery of an extended dust cloud around the WD central star […]
Different routes to the classical limit of backflow
Authors: Mousavi, S., V; Miret-Artes, S.
Journal: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
Publication date: 2022/11/25
Abstract: Decoherence is a well established process for the emergence of classical mechanics in open quantum systems. However, it can have two different origins or mechanisms depending on the dynamics one is considering, speaking then about intrinsic decoherence for isolated systems and environmental decoherence due to dissipation/fluctuations for open systems. This second mechanism can not be considered for backflow since no thermal fluctuation terms can be added in the formalism in order to […]
Modeling of Structure H Carbon Dioxide Clathrate Hydrates: Guest-Lattice Energies, Crystal Structure, and Pressure Dependencies
Authors: Cabrera-Ramirez, Adriana; Prosmiti, Rita
Journal: JOURNAL OF PHYSICAL CHEMISTRY C
Publication date: 2022/09/08
Abstract: We performed first-principles computations to investigate the complex interplay of molecular interaction energies in determining the lattice structure and stability of CO2@sH clathrate hydrates. Density functional theory computations using periodic boundary conditions were employed to characterize energetics and the key structural properties of the sH clathrate crystal under pressure, such as equilibrium lattice volume and bulk modulus. The performance of exchange-correlation functionals together with recently developed dispersion-corrected schemes was evaluated in describing interactions in […]
Mass spectra and appearance energies of cationic fragments for electron ionization of 2-butanol
Authors: Amorim, R. A. A.; Diniz, A. C.; Oliveira, C. B.; Oliveira Junior, O. L.; Jones, D. B.; Blanco, F.; Garcia, G.; Brunger, M. J.; Lopes, M. C. A.
Journal: EUROPEAN PHYSICAL JOURNAL D
Publication date: 2022/11/01
Abstract: In this work, the mass spectrum (MS) and the appearance energies (AEs) of the ionic fragments formed in the collisions of electrons with 2-butanol were studied using a HIDEN-EPIC300 mass spectrometer. The MS was acquired for the electron impact energy of 70 eV, in the mass region of 1-75 amu and […]
History of two mass loss processes in VYCMa Fast outflows carving older ejecta
Authors: Quintana-Lacaci, G.; Velilla-Prieto, L.; Agundez, M.; Fonfria, J. P.; Cernicharo, J.; Decin, L.; Castro-Carrizo, A.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2023/01/05
Abstract: Context. Red supergiant stars (RSGs, M-init=10-40 M-circle dot) are known to eject large amounts of material, as much as half of their initial mass during this evolutionary phase. However, the processes powering the mass ejection in low- and intermediate-mass stars do not work for RSGs and the mechanism that drives the ejection remains unknown. Different mechanisms have been proposed as responsible for this mass ejection […]
Discovery of interstellar NC4NH+: Dicyanopolyynes are indeed abundant in space
Authors: Agundez, M.; Cabezas, C.; Marcelino, N.; Fuentetaja, R.; Tercero, B.; de Vicente, P.; Cernicharo, J.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2023/01/01
Abstract: The previous detection of two species related to the nonpolar molecule cyanogen (NCCN), its protonated form (NCCNH+) and one metastable isomer (CNCN), in cold dense clouds supported the hypothesis that dicyanopolyynes are abundant in space. Here we report the first identification in space of NC4NH+. This cation is the protonated form of NC4N, which is the second member of the series of dicyanopolyynes after NCCN. […]
Certification of a non-projective qudit measurement using multiport beamsplitters
Authors: Martinez, Daniel; Gomez, Esteban S.; Carine, Jaime; Pereira, Luciano; Delgado, Aldo; Walborn, Stephen P.; Tavakoli, Armin; Lima, Gustavo
Journal: NATURE PHYSICS
Publication date: 2022/12/31
Abstract: The most common form of measurement in quantum mechanics projects a wavefunction onto orthogonal states that correspond to definite outcomes. However, generalized quantum measurements that do not fully project quantum states are possible and have an important role in quantum information tasks. Unfortunately, it is difficult to certify that an experiment harvests the advantages made possible by generalized measurements, especially beyond the simplest […]
Optical isolators based on nonreciprocal four-wave mixing
Authors: Muñoz de las Heras, A.; Carusotto, I.
Journal: PHYSICAL REVIEW A
Publication date: 2022/12/29
Abstract: In this work we propose and theoretically characterize optical isolators consisting of an all-dielectric and nonmagnetic resonator featuring an intensity-dependent refractive index and a strong coherent field propagating in a single direction. Such devices can be straightforwardly realized in state-of-the-art integrated photonics plat-forms. The mechanism underlying optical isolation is based on the breaking of optical reciprocity induced by the asymmetric action of four-wave mixing processes coupling a strong propagating pump field with copropagating […]